From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001
From: priyanka
Date: Wed, 24 Jun 2015 15:03:17 +0530
Subject: initial commit / add all books

---
 1847/CH2/EX2.1/Ch02Ex1.sce   | 11 +++++++++++
 1847/CH2/EX2.10/Ch02Ex10.sce | 11 +++++++++++
 1847/CH2/EX2.11/Ch02Ex11.sce | 15 +++++++++++++++
 1847/CH2/EX2.12/Ch02Ex12.sce | 13 +++++++++++++
 1847/CH2/EX2.13/Ch02Ex13.sce | 12 ++++++++++++
 1847/CH2/EX2.14/Ch02Ex14.sce | 13 +++++++++++++
 1847/CH2/EX2.15/Ch02Ex15.sce | 13 +++++++++++++
 1847/CH2/EX2.16/Ch02Ex16.sce | 15 +++++++++++++++
 1847/CH2/EX2.17/Ch02Ex17.sce | 16 ++++++++++++++++
 1847/CH2/EX2.18/Ch02Ex18.sce | 16 ++++++++++++++++
 1847/CH2/EX2.19/Ch02Ex19.sce | 13 +++++++++++++
 1847/CH2/EX2.2/Ch02Ex2.sce   | 10 ++++++++++
 1847/CH2/EX2.20/Ch02Ex20.sce | 17 +++++++++++++++++
 1847/CH2/EX2.21/Ch02Ex21.sce | 11 +++++++++++
 1847/CH2/EX2.22/Ch02Ex22.sce | 12 ++++++++++++
 1847/CH2/EX2.23/Ch02Ex23.sce | 12 ++++++++++++
 1847/CH2/EX2.24/Ch02Ex24.sce | 12 ++++++++++++
 1847/CH2/EX2.25/Ch02Ex25.sce | 10 ++++++++++
 1847/CH2/EX2.26/Ch02Ex26.sce | 12 ++++++++++++
 1847/CH2/EX2.27/Ch02Ex27.sce | 12 ++++++++++++
 1847/CH2/EX2.28/Ch02Ex28.sce | 14 ++++++++++++++
 1847/CH2/EX2.29/Ch02Ex29.sce | 12 ++++++++++++
 1847/CH2/EX2.3/Ch02Ex3.sce   | 15 +++++++++++++++
 1847/CH2/EX2.30/Ch02Ex30.sce | 13 +++++++++++++
 1847/CH2/EX2.31/Ch02Ex31.sce | 19 +++++++++++++++++++
 1847/CH2/EX2.32/Ch02Ex32.sce | 13 +++++++++++++
 1847/CH2/EX2.33/Ch02Ex33.sce | 14 ++++++++++++++
 1847/CH2/EX2.34/Ch02Ex34.sce | 19 +++++++++++++++++++
 1847/CH2/EX2.35/Ch02Ex35.sce | 16 ++++++++++++++++
 1847/CH2/EX2.36/Ch02Ex36.sce | 20 ++++++++++++++++++++
 1847/CH2/EX2.37/Ch02Ex37.sce | 14 ++++++++++++++
 1847/CH2/EX2.38/Ch02Ex38.sce | 19 +++++++++++++++++++
 1847/CH2/EX2.39/Ch02Ex39.sce | 19 +++++++++++++++++++
 1847/CH2/EX2.4/Ch02Ex4.sce   | 11 +++++++++++
 1847/CH2/EX2.40/Ch02Ex40.sce | 14 ++++++++++++++
 1847/CH2/EX2.41/Ch02Ex41.sce | 16 ++++++++++++++++
 1847/CH2/EX2.42/Ch02Ex42.sce | 22 ++++++++++++++++++++++
 1847/CH2/EX2.43/Ch02Ex43.sce | 18 ++++++++++++++++++
 1847/CH2/EX2.44/Ch02Ex44.sce | 16 ++++++++++++++++
 1847/CH2/EX2.46/Ch02Ex46.sce | 16 ++++++++++++++++
 1847/CH2/EX2.47/Ch02Ex47.sce | 14 ++++++++++++++
 1847/CH2/EX2.48/Ch02Ex48.sce | 12 ++++++++++++
 1847/CH2/EX2.49/Ch02Ex49.sce | 11 +++++++++++
 1847/CH2/EX2.5/Ch02Ex5.sce   | 15 +++++++++++++++
 1847/CH2/EX2.50/Ch02Ex50.sce | 11 +++++++++++
 1847/CH2/EX2.51/Ch02Ex51.sce | 13 +++++++++++++
 1847/CH2/EX2.52/Ch02Ex52.sce | 14 ++++++++++++++
 1847/CH2/EX2.53/Ch02Ex53.sce | 12 ++++++++++++
 1847/CH2/EX2.54/Ch02Ex54.sce | 12 ++++++++++++
 1847/CH2/EX2.55/Ch02Ex55.sce | 14 ++++++++++++++
 1847/CH2/EX2.56/Ch02Ex56.sce | 15 +++++++++++++++
 1847/CH2/EX2.57/Ch02Ex57.sce | 14 ++++++++++++++
 1847/CH2/EX2.58/Ch02Ex58.sce | 16 ++++++++++++++++
 1847/CH2/EX2.59/Ch02Ex59.sce | 14 ++++++++++++++
 1847/CH2/EX2.6/Ch02Ex6.sce   | 13 +++++++++++++
 1847/CH2/EX2.60/Ch02Ex60.sce | 12 ++++++++++++
 1847/CH2/EX2.61/Ch02Ex61.sce | 14 ++++++++++++++
 1847/CH2/EX2.62/Ch02Ex62.sce | 13 +++++++++++++
 1847/CH2/EX2.63/Ch02Ex63.sce | 14 ++++++++++++++
 1847/CH2/EX2.64/Ch02Ex64.sce | 16 ++++++++++++++++
 1847/CH2/EX2.65/Ch02Ex65.sce | 13 +++++++++++++
 1847/CH2/EX2.67/Ch02Ex67.sce | 10 ++++++++++
 1847/CH2/EX2.68/Ch02Ex68.sce | 16 ++++++++++++++++
 1847/CH2/EX2.69/Ch02Ex69.sce | 12 ++++++++++++
 1847/CH2/EX2.7/Ch02Ex7.sce   | 15 +++++++++++++++
 1847/CH2/EX2.70/Ch02Ex70.sce | 12 ++++++++++++
 1847/CH2/EX2.71/Ch02Ex71.sce | 11 +++++++++++
 1847/CH2/EX2.72/Ch02Ex72.sce | 12 ++++++++++++
 1847/CH2/EX2.73/Ch02Ex73.sce | 12 ++++++++++++
 1847/CH2/EX2.8/Ch02Ex8.sce   | 15 +++++++++++++++
 1847/CH2/EX2.9/Ch02Ex9.sce   | 12 ++++++++++++
 71 files changed, 985 insertions(+)
 create mode 100755 1847/CH2/EX2.1/Ch02Ex1.sce
 create mode 100755 1847/CH2/EX2.10/Ch02Ex10.sce
 create mode 100755 1847/CH2/EX2.11/Ch02Ex11.sce
 create mode 100755 1847/CH2/EX2.12/Ch02Ex12.sce
 create mode 100755 1847/CH2/EX2.13/Ch02Ex13.sce
 create mode 100755 1847/CH2/EX2.14/Ch02Ex14.sce
 create mode 100755 1847/CH2/EX2.15/Ch02Ex15.sce
 create mode 100755 1847/CH2/EX2.16/Ch02Ex16.sce
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 create mode 100755 1847/CH2/EX2.2/Ch02Ex2.sce
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 create mode 100755 1847/CH2/EX2.26/Ch02Ex26.sce
 create mode 100755 1847/CH2/EX2.27/Ch02Ex27.sce
 create mode 100755 1847/CH2/EX2.28/Ch02Ex28.sce
 create mode 100755 1847/CH2/EX2.29/Ch02Ex29.sce
 create mode 100755 1847/CH2/EX2.3/Ch02Ex3.sce
 create mode 100755 1847/CH2/EX2.30/Ch02Ex30.sce
 create mode 100755 1847/CH2/EX2.31/Ch02Ex31.sce
 create mode 100755 1847/CH2/EX2.32/Ch02Ex32.sce
 create mode 100755 1847/CH2/EX2.33/Ch02Ex33.sce
 create mode 100755 1847/CH2/EX2.34/Ch02Ex34.sce
 create mode 100755 1847/CH2/EX2.35/Ch02Ex35.sce
 create mode 100755 1847/CH2/EX2.36/Ch02Ex36.sce
 create mode 100755 1847/CH2/EX2.37/Ch02Ex37.sce
 create mode 100755 1847/CH2/EX2.38/Ch02Ex38.sce
 create mode 100755 1847/CH2/EX2.39/Ch02Ex39.sce
 create mode 100755 1847/CH2/EX2.4/Ch02Ex4.sce
 create mode 100755 1847/CH2/EX2.40/Ch02Ex40.sce
 create mode 100755 1847/CH2/EX2.41/Ch02Ex41.sce
 create mode 100755 1847/CH2/EX2.42/Ch02Ex42.sce
 create mode 100755 1847/CH2/EX2.43/Ch02Ex43.sce
 create mode 100755 1847/CH2/EX2.44/Ch02Ex44.sce
 create mode 100755 1847/CH2/EX2.46/Ch02Ex46.sce
 create mode 100755 1847/CH2/EX2.47/Ch02Ex47.sce
 create mode 100755 1847/CH2/EX2.48/Ch02Ex48.sce
 create mode 100755 1847/CH2/EX2.49/Ch02Ex49.sce
 create mode 100755 1847/CH2/EX2.5/Ch02Ex5.sce
 create mode 100755 1847/CH2/EX2.50/Ch02Ex50.sce
 create mode 100755 1847/CH2/EX2.51/Ch02Ex51.sce
 create mode 100755 1847/CH2/EX2.52/Ch02Ex52.sce
 create mode 100755 1847/CH2/EX2.53/Ch02Ex53.sce
 create mode 100755 1847/CH2/EX2.54/Ch02Ex54.sce
 create mode 100755 1847/CH2/EX2.55/Ch02Ex55.sce
 create mode 100755 1847/CH2/EX2.56/Ch02Ex56.sce
 create mode 100755 1847/CH2/EX2.57/Ch02Ex57.sce
 create mode 100755 1847/CH2/EX2.58/Ch02Ex58.sce
 create mode 100755 1847/CH2/EX2.59/Ch02Ex59.sce
 create mode 100755 1847/CH2/EX2.6/Ch02Ex6.sce
 create mode 100755 1847/CH2/EX2.60/Ch02Ex60.sce
 create mode 100755 1847/CH2/EX2.61/Ch02Ex61.sce
 create mode 100755 1847/CH2/EX2.62/Ch02Ex62.sce
 create mode 100755 1847/CH2/EX2.63/Ch02Ex63.sce
 create mode 100755 1847/CH2/EX2.64/Ch02Ex64.sce
 create mode 100755 1847/CH2/EX2.65/Ch02Ex65.sce
 create mode 100755 1847/CH2/EX2.67/Ch02Ex67.sce
 create mode 100755 1847/CH2/EX2.68/Ch02Ex68.sce
 create mode 100755 1847/CH2/EX2.69/Ch02Ex69.sce
 create mode 100755 1847/CH2/EX2.7/Ch02Ex7.sce
 create mode 100755 1847/CH2/EX2.70/Ch02Ex70.sce
 create mode 100755 1847/CH2/EX2.71/Ch02Ex71.sce
 create mode 100755 1847/CH2/EX2.72/Ch02Ex72.sce
 create mode 100755 1847/CH2/EX2.73/Ch02Ex73.sce
 create mode 100755 1847/CH2/EX2.8/Ch02Ex8.sce
 create mode 100755 1847/CH2/EX2.9/Ch02Ex9.sce

(limited to '1847/CH2')

diff --git a/1847/CH2/EX2.1/Ch02Ex1.sce b/1847/CH2/EX2.1/Ch02Ex1.sce
new file mode 100755
index 000000000..31c3c090b
--- /dev/null
+++ b/1847/CH2/EX2.1/Ch02Ex1.sce
@@ -0,0 +1,11 @@
+// Scilab Code Ex2.1:: Page-2.9 (2009)
+clc; clear;
+lambda = 5893e-008;  // Wavelength of light used, m
+D = 200;    // Distance of the source from the screen, m
+b = 0.2;    // Fringe separation, cm
+d = lambda*D/b; // Separation between the slits, cm
+
+printf("\nThe separation between the slits = %3.1e cm", d);
+
+// Result 
+// The separation between the slits = 5.9e-002 cm
diff --git a/1847/CH2/EX2.10/Ch02Ex10.sce b/1847/CH2/EX2.10/Ch02Ex10.sce
new file mode 100755
index 000000000..979c40c19
--- /dev/null
+++ b/1847/CH2/EX2.10/Ch02Ex10.sce
@@ -0,0 +1,11 @@
+// Scilab Code Ex2.10:: Page-2.12 (2009)
+clc; clear;
+D = 100;    // Distance between slits and the screen, cm
+d = 0.08;  // Separation between the slits, cm
+b = 2.121/25;  // Fringe width of the interfernce pattern due to biprism, cm
+lambda = b*d/D;     // Wavelength of light in a biprism experiment, cm
+
+printf("\nThe wavelength of light in a biprism experiment = %5.0f angstrom", lambda/1e-008);
+
+// Result
+// The wavelength of light in a biprism experiment =  6787 angstrom 
diff --git a/1847/CH2/EX2.11/Ch02Ex11.sce b/1847/CH2/EX2.11/Ch02Ex11.sce
new file mode 100755
index 000000000..04ad332e5
--- /dev/null
+++ b/1847/CH2/EX2.11/Ch02Ex11.sce
@@ -0,0 +1,15 @@
+// Scilab Code Ex2.11:: Page-2.13 (2009)
+clc; clear;
+alpha = %pi/180;    // Acute angle of biprism, radian
+mu = 1.5;   // Refractive index of biprism
+lambda = 5900e-008;    // Wavelength of light used, cm
+y1 = 10;    // Distance of biprism from the source, cm
+y2 = 100;    // Distance of biprism from the screen, cm
+D = y1 + y2;    // Distance between slits and the screen, cm
+d = 2*(mu-1)*alpha*y1;  // Separation between the slits, cm
+b = lambda*D/d;  // Fringe width of the interfernce pattern due to biprism, cm
+
+printf("\nThe fringe width at a distance of %d cm from biprism = %4.2e cm", y2, b);
+
+// Result
+// The fringe width at a distance of 100 cm from biprism = 3.72e-02 cm  
diff --git a/1847/CH2/EX2.12/Ch02Ex12.sce b/1847/CH2/EX2.12/Ch02Ex12.sce
new file mode 100755
index 000000000..ca474091e
--- /dev/null
+++ b/1847/CH2/EX2.12/Ch02Ex12.sce
@@ -0,0 +1,13 @@
+// Scilab Code Ex2.12:: Page-2.13 (2009)
+clc; clear;
+lambda = 5893e-008;    // Wavelength of light used, cm
+y1 = 10;    // Distance of biprism from the source, cm
+y2 = 100;    // Distance of biprism from the screen, cm
+D = y1 + y2;    // Distance between slits and the screen, cm
+b = 3.5e-02;  // Fringe width of the interfernce pattern due to biprism, cm
+d = lambda*D/b;  // Distance between coherent sources, cm
+
+printf("\nThe distance between coherent sources = %5.3f cm", d);
+
+// Result
+// The distance between coherent sources = 0.185 cm   
diff --git a/1847/CH2/EX2.13/Ch02Ex13.sce b/1847/CH2/EX2.13/Ch02Ex13.sce
new file mode 100755
index 000000000..70ceb318d
--- /dev/null
+++ b/1847/CH2/EX2.13/Ch02Ex13.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.13:: Page-2.13 (2009)
+clc; clear;
+b = 0.125;  // Fringe width of the interfernce pattern due to biprism, cm
+d = 1;  // For simplicity assume distance between sources to be unity, cm
+d_prime = 3/4*d;    // New distance between sources, cm 
+// As b is proportional to 1/d, so
+b_prime = b*d/d_prime;  // New fringe width of the interfernce pattern due to biprism, cm
+
+printf("\nThe new value of fringe width due to reduced slit separation = %5.3f cm", b_prime);
+
+// Result
+// The new value of fringe width due to reduced slit separation = 0.167 cm
diff --git a/1847/CH2/EX2.14/Ch02Ex14.sce b/1847/CH2/EX2.14/Ch02Ex14.sce
new file mode 100755
index 000000000..fc17dbd5f
--- /dev/null
+++ b/1847/CH2/EX2.14/Ch02Ex14.sce
@@ -0,0 +1,13 @@
+// Scilab Code Ex2.14:: Page-2.13 (2009)
+clc; clear;
+b = 0.187;  // Fringe width of the interfernce pattern due to biprism, cm
+y1 = 1;  // For simplicity assume distance between slit and biprism to be unity, cm
+y1_prime = 1.25*y1;    // New distance between slit and biprism, cm
+// As d is directly proportional to y1 and b is directly proportional to d, so
+// b is inversely proportional to y1
+b_prime = b*y1/y1_prime;  // New fringe width of the interfernce pattern due to biprism, cm
+
+printf("\nThe new value of fringe width due to increased slit-biprism separation = %5.3f cm", b_prime);
+
+// Result
+// The new value of fringe width due to increased slit-biprism separation = 0.150 cm 
diff --git a/1847/CH2/EX2.15/Ch02Ex15.sce b/1847/CH2/EX2.15/Ch02Ex15.sce
new file mode 100755
index 000000000..2b62b3419
--- /dev/null
+++ b/1847/CH2/EX2.15/Ch02Ex15.sce
@@ -0,0 +1,13 @@
+// Scilab Code Ex2.15:: Page-2.14 (2009)
+clc; clear;
+d1 = 5e-01; // First distance between images of the slit, cm
+d2 = 2.25e-01; // Second distance between images of the slit, cm
+lambda = 5896e-008; // Wavelength of the light used, cm
+D = 120;    // Distance between screen and the slits, cm
+d = sqrt(d1*d2);    // Geometric mean of distance between the two slits, cm
+b = lambda*D/d;     // Distance between interference bands, cm
+
+printf("\nThe distance between interference bands = %5.3e cm", b);
+
+// Result
+// The distance between interference bands = 2.109e-02 cm 
diff --git a/1847/CH2/EX2.16/Ch02Ex16.sce b/1847/CH2/EX2.16/Ch02Ex16.sce
new file mode 100755
index 000000000..d28280f18
--- /dev/null
+++ b/1847/CH2/EX2.16/Ch02Ex16.sce
@@ -0,0 +1,15 @@
+// Scilab Code Ex2.16:: Page-2.14 (2009)
+clc; clear;
+mu = 1.5;   // Refractive index of biprism
+lambda = 5500e-008;    // Wavelength of light used, cm
+y1 = 25;    // Distance of biprism from the source, cm
+y2 = 150;    // Distance of biprism from the screen, cm
+D = y1 + y2;    // Distance between slits and the screen, cm
+b = 0.05;  // Fringe width of the interfernce pattern due to biprism, cm
+// As d = 2*(mu-1)*alpha*y1, solving for alpha
+alpha = lambda*D/(b*2*(mu-1)*y1)    // Angle of vertex of the biprism, radian
+
+printf("\nThe angle of vertex of the biprism = %6.4f rad", alpha);
+
+// Result
+// The angle of vertex of the biprism = 0.0077 rad 
diff --git a/1847/CH2/EX2.17/Ch02Ex17.sce b/1847/CH2/EX2.17/Ch02Ex17.sce
new file mode 100755
index 000000000..c42bc889a
--- /dev/null
+++ b/1847/CH2/EX2.17/Ch02Ex17.sce
@@ -0,0 +1,16 @@
+// Scilab Code Ex2.17:: Page-2.15 (2009)
+clc; clear;
+theta = 178;    // Vertex angle of biprism, degrees
+alpha = (180-theta)/2*%pi/180;    // Acute angle of biprism, radian
+mu = 1.5;   // Refractive index of biprism
+y1 = 20;    // Distance of biprism from the source, cm
+y2 = 125;    // Distance of biprism from the screen, cm
+D = y1 + y2;    // Distance between slits and the screen, cm
+d = 2*(mu-1)*alpha*y1;  // Separation between the slits, cm
+b = 0.025;  // Fringe width of the interfernce pattern due to biprism, cm
+lambda = b*d/D;    // Wavelength of light used, cm
+
+printf("\nThe wavelength of light used to illuminate slits = %4d angstrom", lambda/1e-08);
+
+// Result
+// The wavelength of light used to illuminate slits = 6018 angstrom 
diff --git a/1847/CH2/EX2.18/Ch02Ex18.sce b/1847/CH2/EX2.18/Ch02Ex18.sce
new file mode 100755
index 000000000..0d4c4f517
--- /dev/null
+++ b/1847/CH2/EX2.18/Ch02Ex18.sce
@@ -0,0 +1,16 @@
+// Scilab Code Ex2.18:: Page-2.15 (2009)
+clc; clear;
+mu = 1.5;   // Refractive index of biprism
+lambda = 6600e-008;    // Wavelength of light used, cm
+y1 = 40;    // Distance of biprism from the source, cm
+y2 = 175;    // Distance of biprism from the screen, cm
+D = y1 + y2;    // Distance between slits and the screen, cm
+b = 0.04;  // Fringe width of the interfernce pattern due to biprism, cm
+// As d = 2*(mu-1)*alpha*y1, solving for alpha
+alpha = lambda*D/(b*2*(mu-1)*y1)    // Acute angle of the biprism, radian
+theta = (%pi-2*alpha);  // Vertex angle of the biprism, radian
+
+printf("\nThe vertex angle of the biprism = %6.2f degrees", theta*180/%pi);
+
+// Result
+// The vertex angle of the biprism = 178.98 degrees 
diff --git a/1847/CH2/EX2.19/Ch02Ex19.sce b/1847/CH2/EX2.19/Ch02Ex19.sce
new file mode 100755
index 000000000..41032271f
--- /dev/null
+++ b/1847/CH2/EX2.19/Ch02Ex19.sce
@@ -0,0 +1,13 @@
+// Scilab Code Ex2.19: : Page-2.16 (2009)
+clc; clear;
+lambda1 = 7000e-008;    // Original wavelength of light, cm
+lambda2 = 5000e-008;    // New wavelength of light, cm
+n1 = 10;    // Order of the fringes with original wavelength
+// As x = n*lambda*D/d, so n*lambda = constant
+// n1*lambda1 = n2*lambda2, solving for n2
+n2 = n1*lambda1/lambda2;    // Order of visible fringe for changed wavelength of light
+ 
+printf("\nThe order of visible fringe for changed wavelength of light = %2d", ceil(n2));
+
+// Result
+// The order of visible fringe for changed wavelength of light = 14 
diff --git a/1847/CH2/EX2.2/Ch02Ex2.sce b/1847/CH2/EX2.2/Ch02Ex2.sce
new file mode 100755
index 000000000..d6285d78c
--- /dev/null
+++ b/1847/CH2/EX2.2/Ch02Ex2.sce
@@ -0,0 +1,10 @@
+// Scilab Code Ex2.2:: Page-2.10 (2009)
+clc; clear;
+d = 0.2; // Separation between the slits, cm
+D = 100;    // Distance of the source from the screen, m
+b = 0.35e-01;    // Fringe separation, cm
+lambda = b*d/D;  // Wavelength of light used, m
+printf("\nThe wavelength of the light = %3.1e cm", lambda);
+
+// Result 
+// The wavelength of the light = 7.0e-005 cm 
diff --git a/1847/CH2/EX2.20/Ch02Ex20.sce b/1847/CH2/EX2.20/Ch02Ex20.sce
new file mode 100755
index 000000000..0d6cba1c8
--- /dev/null
+++ b/1847/CH2/EX2.20/Ch02Ex20.sce
@@ -0,0 +1,17 @@
+// Scilab Code Ex1.20:: Page-2.16 (2009)
+clc; clear;
+y1 = 40;    // Distance between biprism from the slit, cm
+D = 160;    // Distance between slit and the screen, cm
+mu = 1.52;  // Refractive index of material of the prism
+lambda = 5893e-008; // Wavelength of light used, cm
+b = 0.01;   // Fringe width, cm
+// As b = lambda*D/d, solving for d
+d = lambda*D/b;     // Distance between virtual sources, cm
+// But d = 2*y1*(mu-1)*alpha, solving for alpha
+alpha = d/(2*y1*(mu-1))*180/%pi;    // Angle of biprism, degrees
+theta = 180-2*alpha;    // Angle of vertex of biprism, degrees
+
+printf("\nThe angle of vertex of biprism = %5.1f degree", theta);
+
+// Result 
+// The angle of vertex of biprism = 177.4 degree 
diff --git a/1847/CH2/EX2.21/Ch02Ex21.sce b/1847/CH2/EX2.21/Ch02Ex21.sce
new file mode 100755
index 000000000..e9893c0e7
--- /dev/null
+++ b/1847/CH2/EX2.21/Ch02Ex21.sce
@@ -0,0 +1,11 @@
+// Scilab Code Ex2.21: : Page-2.16 (2009)
+clc; clear;
+lambda = 6000e-008;    // Wavelength of light used, cm
+D = 100;    // Distance between slits and the screen, cm
+b = 0.05;  // Fringe width of the interfernce pattern due to biprism, cm
+d = lambda*D/b;  // Distance between coherent sources, cm
+
+printf("\nThe distance between coherent sources = %3.1f mm", d/1e-01);
+
+// Result
+// The distance between coherent sources = 1.2 mm 
diff --git a/1847/CH2/EX2.22/Ch02Ex22.sce b/1847/CH2/EX2.22/Ch02Ex22.sce
new file mode 100755
index 000000000..2d8e2e5a8
--- /dev/null
+++ b/1847/CH2/EX2.22/Ch02Ex22.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.22:: Page-2.19 (2009)
+clc; clear;
+t = 3.2e-04;    // Thickness of the glass sheet, cm
+lambda = 5500e-008;     // Wavelength of light used, cm
+n = 5;      // Order of interference fringes
+// As path difference (mu - 1)*t = n*lambda
+mu = n*lambda/t + 1;    // Refractive indexof the glass sheet
+
+printf("\nThe refractive index of the glass sheet= %4.2f", mu);
+
+// Result 
+// The refractive indexof the glass sheet= 1.86 
diff --git a/1847/CH2/EX2.23/Ch02Ex23.sce b/1847/CH2/EX2.23/Ch02Ex23.sce
new file mode 100755
index 000000000..c993f377c
--- /dev/null
+++ b/1847/CH2/EX2.23/Ch02Ex23.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.23:: Page-2.19 (2009)
+clc; clear;
+t = 2.1e-03;    // Thickness of the glass sheet, cm
+lambda = 5400e-008;     // Wavelength of light used, cm
+n = 11;      // Order of interference fringes
+// As path difference, (mu - 1)*t = n*lambda
+mu = n*lambda/t + 1;    // Refractive index of the glass sheet
+
+printf("\nThe refractive index of the glass sheet = %4.2f", mu);
+
+// Result 
+// The refractive index of the glass sheet= 1.28 
diff --git a/1847/CH2/EX2.24/Ch02Ex24.sce b/1847/CH2/EX2.24/Ch02Ex24.sce
new file mode 100755
index 000000000..a87928fb4
--- /dev/null
+++ b/1847/CH2/EX2.24/Ch02Ex24.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.24:: Page-2.19 (2009)
+clc; clear;
+t = 9.21e-05;    // Thickness of the mica sheet, cm
+mu = 1.5;   // Refractive index of material of sheet
+n = 1;      // Order of interference fringes
+// As path difference, (mu - 1)*t = n*lambda, solving for lambda
+lambda = (mu - 1)*t/n;    // Wavelength of light used, cm
+
+printf("\nThe wavelength of light used = %5.3e cm", lambda);
+
+// Result 
+// The wavelength of light used = 4.605e-005 cm 
diff --git a/1847/CH2/EX2.25/Ch02Ex25.sce b/1847/CH2/EX2.25/Ch02Ex25.sce
new file mode 100755
index 000000000..42eb8f303
--- /dev/null
+++ b/1847/CH2/EX2.25/Ch02Ex25.sce
@@ -0,0 +1,10 @@
+// Scilab Code Ex2.25:: Page-2.19 (2009)
+clc; clear;
+lambda = 5890e-008;     // Wavelength of light used, cm
+mu = 1.5;   // Refractive index of material sheet
+// As shift = 9*lambda*D/d = D/d*(mu - 1)*t, solving for t
+t = 9*lambda/(mu - 1);    // Thickness of the glass sheet, cm
+printf("\nThe thickness of the glass sheet = %4.2e cm", t);
+
+// Result 
+// The thickness of the glass sheet = 1.06e-003 cm 
diff --git a/1847/CH2/EX2.26/Ch02Ex26.sce b/1847/CH2/EX2.26/Ch02Ex26.sce
new file mode 100755
index 000000000..fa9bdac11
--- /dev/null
+++ b/1847/CH2/EX2.26/Ch02Ex26.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.26:: Page-2.20 (2009)
+clc; clear;
+lambda = 5400e-008;     // Wavelength of light used, cm
+mu = 1.7;   // Refractive index of material sheet convering the first slit
+mu_prime = 1.5;     // Refractive index of material sheet convering the seecond slit
+// As shift, S = D/d*(mu - mu_prime)*t = b/lambda*(mu - mu_prime)*t, solving for t
+t = 8*lambda/(mu-mu_prime)    // Thickness of the glass sheet, cm
+
+printf("\nThe thickness of the glass sheet = %4.2e cm", t);
+
+// Result 
+// The thickness of the glass sheet = 2.16e-003 cm 
diff --git a/1847/CH2/EX2.27/Ch02Ex27.sce b/1847/CH2/EX2.27/Ch02Ex27.sce
new file mode 100755
index 000000000..17f3e7297
--- /dev/null
+++ b/1847/CH2/EX2.27/Ch02Ex27.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.27:: Page-2.20 (2009)
+clc; clear;
+t = 21.5e-05;    // Thickness of the glass sheet, cm
+lambda = 5890e-008;     // Wavelength of light used, cm
+n = 1;      // Order of interference fringes
+// As path difference, (mu - 1)*t = n*lambda
+mu = n*lambda/t + 1;    // Refractive indexof the glass sheet
+
+printf("\nThe refractive index of the glass sheet = %5.3f", mu);
+
+// Result 
+// The refractive index of the glass sheet = 1.274 
diff --git a/1847/CH2/EX2.28/Ch02Ex28.sce b/1847/CH2/EX2.28/Ch02Ex28.sce
new file mode 100755
index 000000000..279ee352b
--- /dev/null
+++ b/1847/CH2/EX2.28/Ch02Ex28.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.28:: Page-2.20 (2009)
+clc; clear;
+D = 1;   // For simplicity assume distance between source and slits to be unity, unit
+d = 1;   // For simplicity assume slit separation to be unity, unit
+t = 2.964e-06;    // Thickness of the mica sheet, cm
+mu = 1.5;   // Refractive index of material of shee
+L = poly(0, 'L');
+// As b = b_prime or 2.25*D*L/d = D/d*(mu-1)*t, or we may write
+L = roots(2.25*D*L/d-D/d*(mu-1)*t);     // Wavelength of the light used, m
+
+printf("\nThe wavelength of the light used = %4.0f angstrom", L/1e-010);
+
+// Result 
+// The wavelength of the light used = 6587 angstrom 
diff --git a/1847/CH2/EX2.29/Ch02Ex29.sce b/1847/CH2/EX2.29/Ch02Ex29.sce
new file mode 100755
index 000000000..bfbf2fcaf
--- /dev/null
+++ b/1847/CH2/EX2.29/Ch02Ex29.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.29:: Page-2.21 (2009)
+clc; clear;
+lambda = 5890e-008;     // Wavelength of light used, cm
+n = 5;      // Order of interference fringes
+mu = 1.5;   // Refractive index of the mica sheet
+// As path difference, (mu - 1)*t = n*lambda, solving for t
+t = n*lambda/(mu-1);    // Thickness of the mica sheet, cm
+
+printf("\nThe thickness of the mica sheet = %4.2e cm", t);
+
+// Result 
+// The thickness of the mica sheet = 5.89e-004 cm 
diff --git a/1847/CH2/EX2.3/Ch02Ex3.sce b/1847/CH2/EX2.3/Ch02Ex3.sce
new file mode 100755
index 000000000..e8223f504
--- /dev/null
+++ b/1847/CH2/EX2.3/Ch02Ex3.sce
@@ -0,0 +1,15 @@
+// Scilab Code Ex2.3:: Page-2.10 (2009)
+clc; clear;
+I2 = 1;     // For simplicity assume intensity from slit 2 to be unity, W/sq-m
+I1 = I2*25; // Intensity from slit 1, W/sq-m
+I_ratio = I1/I2;    // Intensity ratio
+a_ratio = sqrt(I_ratio);    // Amplitude ratio
+a2 = 1;     // For simplicity assume amplitude from slit 2 to be unity, m
+a1 = a_ratio*a2;    // Amplitude from slit 1, m
+I_max = (a1 + a2)^2;   // Maximum intensity of wave during interference, W/sq-m
+I_min = (a1 - a2)^2;   // Minimum intensity of wave during interference, W/sq-m
+cf = 4; // Common factor
+printf("\nThe ratio of maximum intentisy to minimum intensity of interference fringes = %d/%d", I_max/cf, I_min/cf); 
+
+// Result 
+// The ratio of maximum intentisy to minimum intensity of interference fringes = 9/4 
diff --git a/1847/CH2/EX2.30/Ch02Ex30.sce b/1847/CH2/EX2.30/Ch02Ex30.sce
new file mode 100755
index 000000000..407c2d44b
--- /dev/null
+++ b/1847/CH2/EX2.30/Ch02Ex30.sce
@@ -0,0 +1,13 @@
+// Scilab Code Ex2.30:: Page-2.21 (2009)
+clc; clear;
+b = 1;      // For simplicity assume fringe width to be unity, cm
+S = 30*b;   // Fringe shift, cm
+lambda = 6600e-008;     // Wavelength of light used, cm
+t = 4.9e-003;       // Thickness of the film, cm
+// As S = b/lambda*(mu-1)*t, solving for mu
+mu = S*lambda/t + 1;       // Refractive index of material from shifting fringe pattern
+
+printf("\nThe refractive index of material from shifting fringe pattern = %3.1f", mu);
+
+// Result 
+// The refractive index of material from shifting fringe pattern = 1.4 
diff --git a/1847/CH2/EX2.31/Ch02Ex31.sce b/1847/CH2/EX2.31/Ch02Ex31.sce
new file mode 100755
index 000000000..04dfa56a7
--- /dev/null
+++ b/1847/CH2/EX2.31/Ch02Ex31.sce
@@ -0,0 +1,19 @@
+// Scilab Code Ex2.31:: Page-2.22 (2009)
+clc; clear;
+mu1 = 1.55;     // Refractive index of mica
+mu2 = 1.52;     // Refractive index of glass
+t = 0.75e-003;  // Thickness of the sheets, m
+d = 0.25e-02;   // Separation between the slits, m
+lambda = 5896e-010; // Wavelength of light used, m
+D = 1.5;    // Distance between the source ans the slits, m
+// Fringe width
+b = lambda*D/d;     // Fringe width, m
+// Optical path difference
+delta_x = (mu1-1)*t-(mu2-1)*t;  // Optical path change, m
+
+printf("\nThe fringe width = %3.1e m", b);
+printf("\nThe optical path change = %5.3e m", delta_x);
+
+// Result 
+// The fringe width = 3.5e-004 m
+// The optical path change = 2.250e-005 m 
diff --git a/1847/CH2/EX2.32/Ch02Ex32.sce b/1847/CH2/EX2.32/Ch02Ex32.sce
new file mode 100755
index 000000000..64d1d897d
--- /dev/null
+++ b/1847/CH2/EX2.32/Ch02Ex32.sce
@@ -0,0 +1,13 @@
+// Scilab Code Ex2.32:: Page-2.22 (2009)
+clc; clear;
+b = 1;      // For simplicity assume fringe width to be unity, cm
+S = 3*b;   // Fringe shift, cm
+lambda = 5890e-008;     // Wavelength of light used, cm
+mu = 1.6;   // Refractive index of the mica sheet
+// As S = b/lambda*(mu-1)*t, solving for t
+t = S*lambda/(mu-1);       // Thickness of the mica sheet, cm
+
+printf("\nThe thickness of the mica sheet = %3.1e m", t/1e+02);
+
+// Result 
+// The thickness of the mica sheet = 2.9e-006 m 
diff --git a/1847/CH2/EX2.33/Ch02Ex33.sce b/1847/CH2/EX2.33/Ch02Ex33.sce
new file mode 100755
index 000000000..98b8df2c0
--- /dev/null
+++ b/1847/CH2/EX2.33/Ch02Ex33.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.33: : Page-2.26 (2009)
+clc; clear;
+mu = 1.5;       // Refractive index of glass
+lambda = 5100e-008; // Wavelength of light used, cm
+i = 30;     // Angle of incidence, degrees
+n = 1;  // Order of interference fringes
+// From Snell's law, mu = sind(i)/sind(r), solving for r
+r = asind(sind(i)/mu);  // Angle of refraction, degrees
+// For a dark fringe in reflection, 2*mu*t*cosd(r) = n*lambda, solving for t
+t = n*lambda/(2*mu*cosd(r));       // Smallest thickness of glass plate for a fringe of minimum intensity, cm
+printf("\nThe smallest thickness of glass plate for a fringe of minimum intensity = %4.2e cm", t);
+
+// Result 
+// The smallest thickness of glass plate for a fringe of minimum intensity = 1.80e-005 cm 
diff --git a/1847/CH2/EX2.34/Ch02Ex34.sce b/1847/CH2/EX2.34/Ch02Ex34.sce
new file mode 100755
index 000000000..866613108
--- /dev/null
+++ b/1847/CH2/EX2.34/Ch02Ex34.sce
@@ -0,0 +1,19 @@
+// Scilab Code Ex2.34:: Page-2.26 (2009)
+clc; clear;
+t = 3.1e-05;    // Thickness of the soap film, cm
+mu = 1.33;      // Refractive index of the soap film
+r = 0;      // Angle of refraction of the light ray on the soap film, degrees
+// For bright fringe in reflected pattern,
+// 2*mu*t*cosd(r) = (2*n+1)*lambda/2
+lambda = zeros(3);  
+for n = 1:1:3
+    lambda(n) = 4*mu*t*cosd(r)/(2*(n-1)+1);     // Wavelengths for n = 1, 2 and 3
+    if lambda(n) > 4000e-008 & lambda(n) < 7500e-008 then
+        lambda_reflected = lambda(n);
+    end
+end
+
+printf("\nThe wavelength reflected strongly from the soap film = %5.3e cm", lambda_reflected);
+
+// Result
+// The wavelength reflected strongly from the soap film = 5.497e-05 cm 
diff --git a/1847/CH2/EX2.35/Ch02Ex35.sce b/1847/CH2/EX2.35/Ch02Ex35.sce
new file mode 100755
index 000000000..d59ffd166
--- /dev/null
+++ b/1847/CH2/EX2.35/Ch02Ex35.sce
@@ -0,0 +1,16 @@
+// Scilab Code Ex2.35:: Page-2.27 (2009)
+clc; clear;
+t = 3.8e-05;    // Thickness of the transparent film, cm
+mu = 1.5;      // Refractive index of the transparent film
+i = 45;     // Angle of incidence of the light ray on the transparent film, degrees
+lambda = 5700e-008;     // Wavelength of light, cm
+// As mu = sind(i)/sind(r), solving for r
+r = asind(sind(i)/mu);
+// For dark fringe in reflected pattern,
+// 2*mu*t*cosd(r) = 2*n*lambda, solving for n
+n = 2*mu*t*cosd(r)/lambda;      // Order of interference of dark band
+
+printf("\nThe order of interference of dark band = %d", ceil(n));
+
+// Result
+// The order of interference of dark band = 2velength reflected strongly from the soap film = 5.497e-05 cm 
diff --git a/1847/CH2/EX2.36/Ch02Ex36.sce b/1847/CH2/EX2.36/Ch02Ex36.sce
new file mode 100755
index 000000000..66f0c63de
--- /dev/null
+++ b/1847/CH2/EX2.36/Ch02Ex36.sce
@@ -0,0 +1,20 @@
+// Scilab Code Ex2.36:: Page-2.27 (2009)
+clc; clear;
+t = 4.5e-05;    // Thickness of the soap film, cm
+mu = 1.33;      // Refractive index of the soap film
+i = 45;     // Angle of incidence of the light ray on the soap film, degrees
+// As mu = sind(i)/sind(r), solving for r
+r = asind(sind(i)/mu);
+// For dark fringe in reflected pattern,
+// 2*mu*t*cosd(r) = n*lambda, solving for lambda for different n's
+lambda = zeros(4);  
+for n = 1:1:4
+    lambda(n) = 2*mu*t*cosd(r)/n;     // Wavelengths for n = 1, 2, 3 and 4
+    if lambda(n) > 4000e-008 & lambda(n) < 7500e-008 then
+        lambda_absent = lambda(n);
+    end
+end
+printf("\nThe absent wavelength of reflected light in the visible spectrum = %4.2e", lambda_absent);
+
+// Result
+// The absent wavelength of reflected light in the visible spectrum = 5.07e-05 
diff --git a/1847/CH2/EX2.37/Ch02Ex37.sce b/1847/CH2/EX2.37/Ch02Ex37.sce
new file mode 100755
index 000000000..f1c8d2073
--- /dev/null
+++ b/1847/CH2/EX2.37/Ch02Ex37.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.37:: Page-2.28 (2009)
+clc; clear;
+mu = 1.6;      // Refractive index of the mica plate
+r = 60;     // Angle of refraction of the light ray on the mica plate, degrees
+lambda = 5500e-008;     // Wavelength of light used, cm
+n = 1;  // Order of interference for minimum thickness
+// For dark fringe in reflected pattern,
+// 2*mu*t*cosd(r) = 2*n*lambda, solving for t
+t = n*lambda/(2*mu*cosd(r));    // Minimum thickness of the plate that will appear dark in the reflection pattern
+
+printf("\nThe minimum thickness of the plate that will appear dark in the reflection pattern = %4.2e cm", t);
+
+// Result
+// The minimum thickness of the plate that will appear dark in the reflection pattern = 3.44e-05 cm 
diff --git a/1847/CH2/EX2.38/Ch02Ex38.sce b/1847/CH2/EX2.38/Ch02Ex38.sce
new file mode 100755
index 000000000..de9e9af8b
--- /dev/null
+++ b/1847/CH2/EX2.38/Ch02Ex38.sce
@@ -0,0 +1,19 @@
+// Scilab Code Ex2.38:: Page-2.28 (2009)
+clc; clear;
+mu = 1.33;      // Refractive index of the thin soap film
+lambda1 = 5500e-008;    // Wavelength of the first dark fringe, cm
+lambda2 = 5400e-008;    // Wavelength of the consecutive dark fringe, cm
+i = 30;     // Angle of incidence of the light ray on the soap film, degrees
+// For overlapping fringes, 
+// n*lambda1 = (n+1)*lambda2, solving for n
+n = lambda2/(lambda1-lambda2);  // Order of interference fringes
+// As mu = sind(i)/sind(r), solving for r
+r = asind(sind(i)/mu);
+// For dark fringe in reflected pattern,
+// 2*mu*t*cosd(r) = 2*n*lambda1, solving for t
+t = n*lambda1/(2*mu*cosd(r));    // Thickness of the thin soap film
+
+printf("\nThe thickness of the thin soap film = %5.3e cm", t);
+
+// Result
+// The thickness of the thin soap film = 1.205e-03 cm 
diff --git a/1847/CH2/EX2.39/Ch02Ex39.sce b/1847/CH2/EX2.39/Ch02Ex39.sce
new file mode 100755
index 000000000..f74275481
--- /dev/null
+++ b/1847/CH2/EX2.39/Ch02Ex39.sce
@@ -0,0 +1,19 @@
+// Scilab Code Ex2.39:: Page-2.29 (2009)
+clc; clear;
+t = 0.75e-06;   // Thickness of the glass plate, m
+mu = 1.5;      // Refractive index of the glass plate
+lambda1 = 4000e-010;    // First wavelength of visible range, cm
+lambda2 = 7000e-010;    // Last wavelength of visible range, cm
+r = 0;     // Angle of refraction for normal incidence, degrees
+n = zeros(2);
+// For bright fringe in reflected pattern,
+// 2*mu*t*cosd(r) = (2*n+1)*lambda/2, solving for n
+// For lambda1
+n(1) = (4*mu*t*cosd(r)/lambda1-1)/2;
+// For lambda2
+n(2) = (4*mu*t*cosd(r)/lambda2-1)/2;
+
+printf("\nFor n = %d and n = %d the light is strongly reflected.", n(1), ceil(n(2)));
+
+// Result
+// For n = 5 and n = 3 the light is strongly reflected. 
diff --git a/1847/CH2/EX2.4/Ch02Ex4.sce b/1847/CH2/EX2.4/Ch02Ex4.sce
new file mode 100755
index 000000000..84a8ee7bc
--- /dev/null
+++ b/1847/CH2/EX2.4/Ch02Ex4.sce
@@ -0,0 +1,11 @@
+// Scilab Code Ex2.4:: Page-2.10 (2009)
+clc; clear;
+d = 0.02; // Separation between the slits, cm
+D = 100;    // Distance of the source from the screen, m
+n = 6;  // No. of bright fringe from the centre
+x = 1.22;   // Position of 6th bright fringe, cm
+lambda = x*d/(n*D);  // Wavelength of light used, m
+printf("\nThe wavelength of the light from coherent sources = %5.3e cm", lambda);
+
+// Result 
+// The wavelength of the light from coherent sources = 4.067e-005 cm 
diff --git a/1847/CH2/EX2.40/Ch02Ex40.sce b/1847/CH2/EX2.40/Ch02Ex40.sce
new file mode 100755
index 000000000..cb48be48d
--- /dev/null
+++ b/1847/CH2/EX2.40/Ch02Ex40.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.40:: Page-2.30 (2009)
+clc; clear;
+mu = 1.45;      // Refractive index of the film
+lambda = 5500e-010;    // First wavelength of visible range, cm
+r = 0;     // Angle of refraction for normal incidence, degrees
+n = 0;      // Order of interference is zero for minimum thickness
+// For bright fringe in reflected pattern,
+// 2*mu*t*cosd(r) = (2*n+1)*lambda/2, solving for t
+t = (2*n+1)*lambda/(4*mu*cosd(r));    // Minimum thickness of the film for which light is strongly reflected
+
+printf("\nThe minimum thickness of the film for which light is strongly reflected = %4.2e cm", t);
+
+// Result
+// The minimum thickness of the film for which light is strongly reflected = 9.48e-08 cm 
diff --git a/1847/CH2/EX2.41/Ch02Ex41.sce b/1847/CH2/EX2.41/Ch02Ex41.sce
new file mode 100755
index 000000000..103eb888e
--- /dev/null
+++ b/1847/CH2/EX2.41/Ch02Ex41.sce
@@ -0,0 +1,16 @@
+// Scilab Code Ex2.41:: Page-2.30 (2009)
+clc; clear;
+mu = 5/4;      // Refractive index of the film
+lambda = 5890e-010;    // Wavelength of visible light, cm
+i = 45;     // Angle of incidence, degrees
+n = 1;      // Order of interference is unity for minimum thickness in dark reflected pattern
+// As mu = sind(i)/sind(r), solving for r
+r = asind(sind(i)/mu);
+// For dark fringe in reflected pattern,
+// 2*mu*t*cosd(r) = n*lambda, solving for t
+t = n*lambda/(2*mu*cosd(r));    // Thickness of the soap film for dark fringe in reflected pattern
+
+printf("\nThe thickness of the soap film for dark fringe in reflected pattern = %5.3e cm", t);
+
+// Result
+// The thickness of the soap film for dark fringe in reflected pattern = 2.857e-07 cm 
diff --git a/1847/CH2/EX2.42/Ch02Ex42.sce b/1847/CH2/EX2.42/Ch02Ex42.sce
new file mode 100755
index 000000000..e7c18c502
--- /dev/null
+++ b/1847/CH2/EX2.42/Ch02Ex42.sce
@@ -0,0 +1,22 @@
+// Scilab Code Ex2.42:: Page-2.30 (2009)
+clc; clear;
+mu = 1.5;      // Refractive index of the plate
+t = 0.5e-006;   // Thickness of the plate, m
+r = 0;      // Angle of refraction for normal incidence, degrees
+// For bright fringe in reflected pattern,
+// 2*mu*t*cosd(r) = (2*n+1)*lambda/2, solving for lambda for different n's
+lambda = zeros(4);  
+for n = 0:1:3
+    lambda(n+1) = 4*mu*t*cosd(r)/(2*n+1);     // Wavelengths for n = 0, 1, 2 and 3
+    lambda_strong = lambda(n+1);
+    if lambda(n+1) >= 4000e-010 & lambda(n+1) <= 7500e-010 then
+          if lambda_strong > lambda(n+1)  then  // Search for the stronger wavelength
+              lambda_strong = lambda(n+1);
+          end
+    end
+end
+
+printf("\nFor n = %d, %4.0f angstrom will be reflected strongly", n, lambda_strong/1e-010);
+
+// Result
+// For n = 3, 4286 angstrom will be reflected strongly 
diff --git a/1847/CH2/EX2.43/Ch02Ex43.sce b/1847/CH2/EX2.43/Ch02Ex43.sce
new file mode 100755
index 000000000..877b3d976
--- /dev/null
+++ b/1847/CH2/EX2.43/Ch02Ex43.sce
@@ -0,0 +1,18 @@
+// Scilab Code Ex2.43:: Page-2.31(2009)
+clc; clear;
+mu = 1.33;      // Refractive index of the film
+i = asind(0.8);      // Angle of refraction for normal incidence, degrees
+// As mu = sind(i)/sind(r), solving for r
+r = asind(sind(i)/mu);
+lambda1 = 6100e-010;    // First wavelength of dark band, m
+lambda2 = 6000e-010;    // Second wavelength of dark band, m
+// For consecutive overlapping wavelenghts
+// n*lambda1 = (n+1)*lambda2, solving for n
+n = lambda2/(lambda1-lambda2);
+// For dark fringe in reflected pattern,
+// 2*mu*t*cosd(r) = n*lambda1, solving for t
+t = n*lambda1/(2*mu*cosd(r));   // Thickness of the film with incident white light. m
+printf("\nThickness of the film with incident white light = %3.1e m", t);
+
+// Result
+// Thickness of the film with incident white light = 1.7e-05 m 
diff --git a/1847/CH2/EX2.44/Ch02Ex44.sce b/1847/CH2/EX2.44/Ch02Ex44.sce
new file mode 100755
index 000000000..05bf42f91
--- /dev/null
+++ b/1847/CH2/EX2.44/Ch02Ex44.sce
@@ -0,0 +1,16 @@
+// Scilab Code Ex2.44:: Page-2.31(2009)
+clc; clear;
+mu = 1.5;      // Refractive index of the film
+i = 45;      // Angle of incidence, degrees
+// As mu = sind(i)/sind(r), solving for r
+r = asind(sind(i)/mu);
+lambda = 5500e-010;    // Wavelength of parallel beam of light, m
+n = 15;     // Order of dark band
+// For dark fringe in reflected pattern,
+// 2*mu*t*cosd(r) = n*lambda, solving for t
+t = n*lambda/(2*mu*cosd(r));   // Thickness of the film with incident parallel beam of light. m
+
+printf("\nThe thickness of the film with paralle beam of yellow light = %4.2e m", t);
+
+// Result
+// The thickness of the film with paralle beam of yellow light = 3.12e-06 m
diff --git a/1847/CH2/EX2.46/Ch02Ex46.sce b/1847/CH2/EX2.46/Ch02Ex46.sce
new file mode 100755
index 000000000..120a2d8ca
--- /dev/null
+++ b/1847/CH2/EX2.46/Ch02Ex46.sce
@@ -0,0 +1,16 @@
+// Scilab Code Ex2.46:: Page-2.33(2009)
+clc; clear;
+V = 0.58e-006;   // Volume of oil, metre cube
+A = 2.5;        // Area of water surface, metre square
+t = V/A;    // Thickness of film, m
+r = 0;      // Angle of refraction for normal incidence, degrees
+n = 1;      // Order of interference for minimum thickness
+lambda = 4700e-010;     // Wavelength of light used, m
+// For dark fringe in reflected pattern,
+// 2*mu*t*cosd(r) = n*lambda, solving for mu
+mu = n*lambda/(2*t*cosd(r));    // Refractive index of oil
+
+printf("\nThe refractive index of oil = %5.3f", mu);
+
+// Result
+// The refractive index of oil = 1.013 
diff --git a/1847/CH2/EX2.47/Ch02Ex47.sce b/1847/CH2/EX2.47/Ch02Ex47.sce
new file mode 100755
index 000000000..c78aa5126
--- /dev/null
+++ b/1847/CH2/EX2.47/Ch02Ex47.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.47:: Page-2.33(2009)
+clc; clear;
+mu = 1.46;      // Refractive index of the soap film
+lambda = 6000e-010;     // Wavelength of light used, m
+r = 0;      // Angle of refraction for normal incidence, degrees
+n = 0;      // Order of interference for minimum thickness
+// For bright fringe in reflected pattern,
+// 2*mu*t*cosd(r) = (2*n+1)*lambda/2, solving for mu
+t = (2*n+1)*lambda/(4*mu*cosd(r));  // Thickness of soap film, m
+
+printf("\nThe thickness of soap film = %5.3e m", t);
+
+// Result
+// The thickness of soap film = 1.027e-07 m 
diff --git a/1847/CH2/EX2.48/Ch02Ex48.sce b/1847/CH2/EX2.48/Ch02Ex48.sce
new file mode 100755
index 000000000..8c87bc5e6
--- /dev/null
+++ b/1847/CH2/EX2.48/Ch02Ex48.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.48: : Page-2.35(2009)
+clc; clear;
+mu = 1.4;      // Refractive index of the film
+alpha = 1.07e-004;  // Acute angle of the wedge, radian
+b = 0.2;    // Fringe width, cm
+// As b = lambda/(2*mu*alpha), solving for lambda
+lambda = 2*mu*alpha*b;  // Wavelength of light falling on wedge shaped film, m
+
+printf("\nThe wavelength of light falling on wedge shaped film = %4d ansgtrom", lambda/1e-008);
+
+// Result
+// The wavelength of light falling on wedge shaped film = 5991 ansgtrom 
diff --git a/1847/CH2/EX2.49/Ch02Ex49.sce b/1847/CH2/EX2.49/Ch02Ex49.sce
new file mode 100755
index 000000000..9c266f6b4
--- /dev/null
+++ b/1847/CH2/EX2.49/Ch02Ex49.sce
@@ -0,0 +1,11 @@
+// Scilab Code Ex2.49:: Page-2.35(2009)
+clc; clear;
+mu = 1.4;      // Refractive index of the film
+lambda = 5500e-008; // Wavelength of the light, cm
+// As alpha = (delta_t)/x and x = 10*b; b = lambda/(2*mu*alpha), solving for dt
+delta_t = 10*lambda/(2*mu);     // Difference between the thicknesses of the films, cm
+
+printf("\nDifference between the thicknesses of the films = %4.2e cm", delta_t);
+
+// Result
+// Difference between the thicknesses of the films = 1.96e-04 cm 
diff --git a/1847/CH2/EX2.5/Ch02Ex5.sce b/1847/CH2/EX2.5/Ch02Ex5.sce
new file mode 100755
index 000000000..8528af407
--- /dev/null
+++ b/1847/CH2/EX2.5/Ch02Ex5.sce
@@ -0,0 +1,15 @@
+// Scilab Code Ex2.5:: Page-2.10 (2009)
+clc; clear;
+lambda1 = 5890e-008;    // Wavelength of D1 line of sodium, cm
+lambda2 = 5896e-008;    // Wavelength of D2 line of sodium, cm
+D = 120;    // Distance between source and the screen, cm
+d = 0.025;  // Separation between the slits, cm
+n = 4;  // Order of dark fringe
+x1 = (2*n+1)*lambda1*D/(2*d);   // Position of 4th dark fringe due to D1 line, cm
+x2 = (2*n+1)*lambda2*D/(2*d);   // Position of 4th dark fringe due to D2 line, cm
+delta_x = x2-x1;    // Fringe separation, cm
+
+printf("\nThe separation between fourth order dark fringes = %4.2e cm", x2-x1);
+
+// Result
+// The separation between fourth order dark fringes = 1.30e-03 cm 
diff --git a/1847/CH2/EX2.50/Ch02Ex50.sce b/1847/CH2/EX2.50/Ch02Ex50.sce
new file mode 100755
index 000000000..74a0c166a
--- /dev/null
+++ b/1847/CH2/EX2.50/Ch02Ex50.sce
@@ -0,0 +1,11 @@
+// Scilab Code Ex2.50:: Page-2.36(2009)
+clc; clear;
+mu = 1.6;      // Refractive index of the film
+lambda = 5500e-008; // Wavelength of the light, cm
+b = 0.1;       // Fringe width, cm
+// As b = lambda/(2*mu*alpha), solving for alpha
+alpha = lambda/(2*mu*b);    // Angle of thin wedge shaped film, radian
+printf("\nAngle of thin wedge shaped film = %3.1e radian", alpha);
+
+// Result
+// Angle of thin wedge shaped film = 1.7e-04 radian 
diff --git a/1847/CH2/EX2.51/Ch02Ex51.sce b/1847/CH2/EX2.51/Ch02Ex51.sce
new file mode 100755
index 000000000..baa510ab2
--- /dev/null
+++ b/1847/CH2/EX2.51/Ch02Ex51.sce
@@ -0,0 +1,13 @@
+// Scilab Code Ex2.51:: Page-2.36(2009)
+clc; clear;
+mu = 1.5;      // Refractive index of the film
+b = 0.20;       // Fringe width, cm
+theta = 25/(60*60)*%pi/180;     // Angle of the wedge, radian
+// As b = lambda/(2*mu*theta), solving for lambda
+lambda = 2*mu*b*theta;    // Wavelength of light used to illuminate a wedge shaped film, cm
+
+printf("\nThe wavelength of light used to illuminate a wedge shaped film = %4d angstrom", lambda/1e-008);
+
+// Result
+// The wavelength of light used to illuminate a wedge shaped film = 7272 angstrom
+// The answer is given wrong in the textbook
diff --git a/1847/CH2/EX2.52/Ch02Ex52.sce b/1847/CH2/EX2.52/Ch02Ex52.sce
new file mode 100755
index 000000000..b624d0b68
--- /dev/null
+++ b/1847/CH2/EX2.52/Ch02Ex52.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.52:: Page-2.36(2009)
+clc; clear;
+lambda = 5893e-010;     // Wavelength of light used, m
+mu = 1;      // Refractive index of the glass
+b = 1;       // Assume fringe width to be unity, cm
+// As b = l/20, solving for l
+l = b*20;       // Length of the film, m
+// As b = lambda/(2*mu*theta) and theta = t/l, solving for t
+t = lambda*l/(2*mu);    // Thickness of the wire separating two glass surfaces, m
+
+printf("\nThe thickness of the wire separating two glass surfaces = %4.2e m", t);
+
+// Result
+// The thickness of the wire separating two glass surfaces = 5.89e-06 m 
diff --git a/1847/CH2/EX2.53/Ch02Ex53.sce b/1847/CH2/EX2.53/Ch02Ex53.sce
new file mode 100755
index 000000000..5cd4bd562
--- /dev/null
+++ b/1847/CH2/EX2.53/Ch02Ex53.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.53:: Page-2.37(2009)
+clc; clear;
+mu = 1;      // Refractive index of the air film
+b = 1.5/25;       // Fringe width, cm
+lambda = 5893e-008;    // Wavelength of light used to illuminate a wedge shaped film, cm
+// As b = lambda/(2*mu*theta), solving for theta
+theta = lambda/(2*mu*b);    // Angle of the wedge, radian
+
+printf("\nThe angle of the wedge shaped air film = %5.3f degrees", theta*180/%pi);
+
+// Result
+// The angle of the wedge shaped air film = 0.028 degrees 
diff --git a/1847/CH2/EX2.54/Ch02Ex54.sce b/1847/CH2/EX2.54/Ch02Ex54.sce
new file mode 100755
index 000000000..9125e8dae
--- /dev/null
+++ b/1847/CH2/EX2.54/Ch02Ex54.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.54:: Page-2.37(2009)
+clc; clear;
+mu = 1.45;      // Refractive index of the film
+b = 1/10;       // Fringe width, cm
+lambda = 6600e-008;    // Wavelength of light used to illuminate a wedge shaped film, cm
+// As b = lambda/(2*mu*theta), solving for theta
+theta = lambda/(2*mu*b);    // Angle of the wedge, radian
+
+printf("\nThe acute angle of the wedge shaped film = %6.4f degrees", theta*180/%pi);
+
+// Result
+// The acute angle of the wedge shaped film = 0.0130 degrees
diff --git a/1847/CH2/EX2.55/Ch02Ex55.sce b/1847/CH2/EX2.55/Ch02Ex55.sce
new file mode 100755
index 000000000..4569279ff
--- /dev/null
+++ b/1847/CH2/EX2.55/Ch02Ex55.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.55:: Page-2.46(2009)
+clc; clear;
+lambda1 = 6000e-008;    // First visible wavelength, cm
+lambda2 = 4500e-008;    // Second visible wavelength, cm
+R = 100;        // Radius of curvature of the lens, cm
+// As diameter of nth dark ring due to lambda1 is
+// D_n^2 = 4*n*R*lambda1 and D_nplus1^ = 4*(n+1)*R*lambda2, so that D_n^2 = D_nplus1^2 gives
+n = lambda2/(lambda1-lambda2);      // Order of interference for dark fringes
+D_n = sqrt(4*n*R*lambda1);      // Diameter of nth dark ring due to lambda1 
+
+printf("\nThe diameter of nth dark ring due to wavelength of %4d angstrom = %4.2f cm", lambda1/1e-008, D_n);
+
+// Result
+// The diameter of nth dark ring due to wavelength of 6000 angstrom = 0.27 cm 
diff --git a/1847/CH2/EX2.56/Ch02Ex56.sce b/1847/CH2/EX2.56/Ch02Ex56.sce
new file mode 100755
index 000000000..8dd15704d
--- /dev/null
+++ b/1847/CH2/EX2.56/Ch02Ex56.sce
@@ -0,0 +1,15 @@
+// Scilab Code Ex2.56:: Page-2.46(2009)
+clc; clear;
+R = 1;      // For simplicity assume radius of curvature of the lens to be unity, cm
+D_n = 0.251;     // Diameter of 3rd dark ring, cm
+D_nplusp = 0.548;     // Diameter of 9th dark ring, cm
+n = 3;      // Order of 3rd Newton ring
+p = 9 - n;    // Order of 6th Newton ring from 3rd ring
+// As D_nplusp^2 - D_n^2 = 4*p*R*lambda, solving for lambda
+lambda = (D_nplusp^2 - D_n^2)/(4*p*R);      // Wavelength of light used
+D_15 = sqrt(D_n^2+4*(15-n)*lambda*R);       // Diameter of 15th dark ring, cm
+
+printf("\nThe diameter of 15th dark ring = %5.3f cm", D_15);
+
+// Result
+// The diameter of 15th dark ring = 0.733 cm 
diff --git a/1847/CH2/EX2.57/Ch02Ex57.sce b/1847/CH2/EX2.57/Ch02Ex57.sce
new file mode 100755
index 000000000..cf857619e
--- /dev/null
+++ b/1847/CH2/EX2.57/Ch02Ex57.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.57: : Page-2.47(2009)
+clc; clear;
+R = 1;      // For simplicity assume radius of curvature of the lens to be unity, cm
+n = 30;      // Order of 3rd Newton ring
+D_30 = 1;   // Assume diameter of thirtieth ring to be unity, cm
+// As D_30^2 = 4*n*R*lambda, solving for lambda
+lambda = D_30^2/(4*n*R);    // Wavelength of light used, cm
+D_n = 3*D_30;       // Diameter of nth dark ring having thrice the diameter of the thirtieth ring, cm
+n = D_n^2/(4*R*lambda);     // Order of a dark ring having thrice the diameter of the thirtieth ring
+
+printf("\nThe order of the dark ring having thrice the diameter of the thirtieth ring = %3d", n);
+
+// Result
+// The order of the dark ring having thrice the diameter of the thirtieth ring = 270 
diff --git a/1847/CH2/EX2.58/Ch02Ex58.sce b/1847/CH2/EX2.58/Ch02Ex58.sce
new file mode 100755
index 000000000..5f0e8608f
--- /dev/null
+++ b/1847/CH2/EX2.58/Ch02Ex58.sce
@@ -0,0 +1,16 @@
+// Scilab Code Ex2.58:: Page-2.47(2009)
+clc; clear;
+n = 15;      // Order of 15rd Newton ring
+D_15 = 0.75;   // Diameter of fifteenth dark ring, cm
+lambda = 5890e-008;     // Wavelength of light used, cm
+// As D_15^2 = 4*15*R*lambda, solving for R
+R = D_15^2/(4*15*lambda);    // Radius of curvature of lens, cm
+// For dark ring, 2*t = n*lambda, solving for t
+t = n*lambda/2;     // Thickness of air film, cm
+
+printf("\nThe radius of curvature of lens = %5.1f cm", R);
+printf("\nThe thickness of air film = %3.1e cm", t);
+
+// Result
+// The radius of curvature of lens = 159.2 cm
+// The thickness of air film = 4.4e-004 cm 
diff --git a/1847/CH2/EX2.59/Ch02Ex59.sce b/1847/CH2/EX2.59/Ch02Ex59.sce
new file mode 100755
index 000000000..b851b122c
--- /dev/null
+++ b/1847/CH2/EX2.59/Ch02Ex59.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.59:: Page-2.47(2009)
+clc; clear;
+D_15 = 1.62;        // Diameter of 15th dark ring with air film, cm
+D_15_prime = 1.47;        // Diameter of 15th dark ring with liquid, cm
+R = 1;      // For simplicity assume radius of curvature to be unity, cm
+n = 15;      // Order of 15rd Newton ring
+// As for ring with air film, D_15^2 = 4*15*R*lambda, solving for lambda
+lambda = D_15^2/(4*15*R);    // Wavelength of light used, cm
+// As for ring with liquid, D_15_prime^2 = 4*15*R*lambda/mu, solving for mu
+mu = 4*15*R*lambda/D_15_prime^2;        // Refractive index of the liquid
+printf("\nThe refractive index of the liquid = %4.2f", mu)
+
+// Result
+// The refractive index of the liquid = 1.21 
diff --git a/1847/CH2/EX2.6/Ch02Ex6.sce b/1847/CH2/EX2.6/Ch02Ex6.sce
new file mode 100755
index 000000000..67b144ed8
--- /dev/null
+++ b/1847/CH2/EX2.6/Ch02Ex6.sce
@@ -0,0 +1,13 @@
+// Scilab Code Ex2.6:: Page-2.11 (2009)
+clc; clear;
+lambda = 5500e-008;    // Wavelength of light used, cm
+Y1 = 10;    // Distance of biprism from the source, cm
+Y2 = 90;    // Distance of biprism from the screen, cm
+D = Y1 + Y2;    // Distance between slits and the screen, cm
+b = 8.526e-02;  // Fringe width, cm
+d = lambda*D/b;  // Separation between the slits, cm
+
+printf("\nThe distance between two coherent sources = %4.2e cm", d);
+
+// Result
+// The distance between two coherent sources = 6.45e-02 cm 
diff --git a/1847/CH2/EX2.60/Ch02Ex60.sce b/1847/CH2/EX2.60/Ch02Ex60.sce
new file mode 100755
index 000000000..d6472b481
--- /dev/null
+++ b/1847/CH2/EX2.60/Ch02Ex60.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.60:: Page-2.48(2009)
+clc; clear;
+D_10 = 0.48;        // Diameter of 10th dark ring with air film, cm
+D_3 = 0.291;        // Diameter of 3rd dark ring with air film, cm
+p = 7;      // Order of the 10th ring next to the 3rd ring
+R = 90;     // Radius of curvature of the lens, cm
+lambda = (D_10^2-D_3^2)/(4*p*R);      // Wavelength of light used in Newton rings experiment
+
+printf("\nThe wavelength of light used in Newton rings experiment = %4d angstrom", lambda/1e-008);
+
+// Result
+// The wavelength of light used in Newton rings experiment = 5782 angstrom 
diff --git a/1847/CH2/EX2.61/Ch02Ex61.sce b/1847/CH2/EX2.61/Ch02Ex61.sce
new file mode 100755
index 000000000..2c35a0cb2
--- /dev/null
+++ b/1847/CH2/EX2.61/Ch02Ex61.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.61:: Page-2.48(2009)
+clc; clear;
+R1 = 200;       // Radius of curvature of the convex surface, cm
+R2 = 250;       // Radius of curvature of the concave surface, cm
+lambda = 5500e-008; // Wavelength of light used, cm
+n = 15;     // Order of interfernce Newton ring
+// As r_n^2*(1/R1-1/R2) = (2*n-1)*lambda/2, solving for r_n
+r_n = sqrt((2*n-1)*lambda/(2*(1/R1-1/R2)));     // Radius of nth ring, cm
+D_15 = 2*r_n;       // Daimeter of 15th bright ring, cm
+
+printf("\nThe daimeter of 15th bright ring = %4.2f cm", D_15);
+
+// Result
+// The daimeter of 15th bright ring = 1.79 cm 
diff --git a/1847/CH2/EX2.62/Ch02Ex62.sce b/1847/CH2/EX2.62/Ch02Ex62.sce
new file mode 100755
index 000000000..98ebd9c27
--- /dev/null
+++ b/1847/CH2/EX2.62/Ch02Ex62.sce
@@ -0,0 +1,13 @@
+// Scilab Code Ex2.62:: Page-2.49(2009)
+clc; clear;
+R = 80;       // Radius of curvature of the convex surface, cm
+D5 = 0.192;    // Diameter of 5th dark ring, cm
+D25 = 0.555;    // Diameter of 25th dark ring, cm
+n = 5;     // Order of interfernce Newton ring
+P = 25 - n;
+lambda = (D25^2 - D5^2)/(4*P*R);    // Wavelength of light used, cm
+printf("\nThe wavelength of light used = %5.3e cm", lambda);
+
+// Result
+// The wavelength of light used = 4.237e-005 cm 
+// The expression for lambda is given wrong in the textbook but solved correctly
diff --git a/1847/CH2/EX2.63/Ch02Ex63.sce b/1847/CH2/EX2.63/Ch02Ex63.sce
new file mode 100755
index 000000000..03b413bf6
--- /dev/null
+++ b/1847/CH2/EX2.63/Ch02Ex63.sce
@@ -0,0 +1,14 @@
+// Scilab Code Ex2.63:: Page-2.49(2009)
+clc; clear;
+R1 = 4;       // Radius of curvature of the convex surface, m
+R2 = 5;       // Radius of curvature of the concave surface, m
+lambda = 6600e-010; // Wavelength of light used, cm
+n = 15;     // Order of Newton ring
+// As D_n^2*(1/R1-1/R2) = 4*n*lambda, solving for D_n
+D_15 = sqrt(4*n*lambda/(1/R1-1/R2));     // Diameter of 15th dark ring, cm
+
+printf("\nThe diameter of %dth dark ring = %4.2e m", n, D_15);
+
+// Result
+// The diameter of 15th dark ring = 2.81e-002 m 
+// The answer is given wrong in the textbook (the square root is not solved)
diff --git a/1847/CH2/EX2.64/Ch02Ex64.sce b/1847/CH2/EX2.64/Ch02Ex64.sce
new file mode 100755
index 000000000..ec9ea0b47
--- /dev/null
+++ b/1847/CH2/EX2.64/Ch02Ex64.sce
@@ -0,0 +1,16 @@
+// Scilab Code Ex2.64:: Page-2.49(2009)
+clc; clear;
+lambda1 = 6000e-008;    // First visible wavelength, cm
+lambda2 = 4500e-008;    // Second visible wavelength, cm
+R = 120;        // Radius of curvature of the lens, cm
+// As diameter of nth dark ring due to lambda1 is
+// D_n^2 = 4*n*R*lambda1 and D_nplus1^ = 4*(n+1)*R*lambda2, so that D_n^2 = D_nplus1^2 gives
+n = lambda2/(lambda1-lambda2);      // Order of interference for dark fringes
+printf("\nThe value of n = %d", n);
+n = 15;     // Order of interference fringe
+D_n = sqrt(4*n*R*lambda1);      // Diameter of nth dark ring due to lambda1 
+printf("\nThe diameter of 15th dark ring due to wavelength of %4d angstrom = %4.2f cm", lambda1/1e-008, D_n);
+
+// Result
+// The value of n = 3
+// The diameter of 15th dark ring due to wavelength of 6000 angstrom = 0.66 cm 
diff --git a/1847/CH2/EX2.65/Ch02Ex65.sce b/1847/CH2/EX2.65/Ch02Ex65.sce
new file mode 100755
index 000000000..216e00327
--- /dev/null
+++ b/1847/CH2/EX2.65/Ch02Ex65.sce
@@ -0,0 +1,13 @@
+// Scilab Code Ex2.65:: Page-2.49(2009)
+clc; clear;
+lambda = 5896e-008;    // Wavelength of light used, cm
+R = 100;        // Radius of curvature of the lens, cm
+D10 = 0.4;      // Diametre of 10th dark ring, cm
+n = 10;     // Order of Newton ring
+// As for a dark ring, 2*mu*t = n*lambda and 2*t = (D10/2)^2/R, solving for mu
+mu = 4*n*lambda*R/D10^2;    // Refractive index of the liquid filled into container
+
+printf("\nThe refractive index of the liquid filled into container = %4.2f", mu);
+
+// Result
+// The refractive index of the liquid filled into container = 1.47 
diff --git a/1847/CH2/EX2.67/Ch02Ex67.sce b/1847/CH2/EX2.67/Ch02Ex67.sce
new file mode 100755
index 000000000..04546946b
--- /dev/null
+++ b/1847/CH2/EX2.67/Ch02Ex67.sce
@@ -0,0 +1,10 @@
+// Scilab Code Ex2.67:: Page-2.50(2009)
+clc; clear;
+Dn = 1.8;       // Diameter of 15th dark ring, cm
+Dn_prime = 1.67;    // Diameter of 15th dark ring with liquid, cm
+mu = (Dn/Dn_prime)^2;   // Refractive index of the liquid
+
+printf("\nThe refractive index of the liquid = %4.2f", mu);
+
+// Result
+// The refractive index of the liquid = 1.16 
diff --git a/1847/CH2/EX2.68/Ch02Ex68.sce b/1847/CH2/EX2.68/Ch02Ex68.sce
new file mode 100755
index 000000000..17f5740fe
--- /dev/null
+++ b/1847/CH2/EX2.68/Ch02Ex68.sce
@@ -0,0 +1,16 @@
+// Scilab Code Ex2.68:: Page-2.51(2009)
+clc; clear;
+R = 1;      // For simplicity assume radius of curvature to be unity, cm
+D8 = 0.45;       // Diameter of 8th dark ring, cm
+D15 = 0.81;     // Diameter of 15th dark ring, cm
+n = 8;          // Order of 8th Newton ring
+p = 7;          // Order of 7th Newton ring after 8th ring
+lambda = (D15^2-D8^2)/(4*p*R);      // Wavelength of light used, cm
+// As D18^2-D15^2 = 4*p*lambda*R
+p = 3;      // For 18th and 15th rings
+D18 = sqrt(D15^2+4*p*lambda*R);     // Diameter of 18th ring, cm
+
+printf("\nThe diameter of 18th dark ring = %6.4f cm", D18);
+
+// Result
+// The diameter of 18th dark ring = 0.9222 cm 
diff --git a/1847/CH2/EX2.69/Ch02Ex69.sce b/1847/CH2/EX2.69/Ch02Ex69.sce
new file mode 100755
index 000000000..52fe7d113
--- /dev/null
+++ b/1847/CH2/EX2.69/Ch02Ex69.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.69:: Page-2.51(2009)
+clc; clear;
+R = 100;      // Radius of curvature of plano-convex lens, cm
+D15 = 0.590;     // Diameter of 15th dark ring, cm
+D5 = 0.336;     // Diameter of 5th dark ring, cm
+p = 10;          // Order of 10th Newton ring after 5th ring
+lambda = (D15^2-D5^2)/(4*p*R);      // Wavelength of light used, cm
+
+printf("\nThe wavelength of light used = %4.0f ansgtrom", lambda/1e-008);
+
+// Result
+// The wavelength of light used = 5880 ansgtrom 
diff --git a/1847/CH2/EX2.7/Ch02Ex7.sce b/1847/CH2/EX2.7/Ch02Ex7.sce
new file mode 100755
index 000000000..9a8b84c26
--- /dev/null
+++ b/1847/CH2/EX2.7/Ch02Ex7.sce
@@ -0,0 +1,15 @@
+// Scilab Code Ex2.7:: Page-2.11 (2009)
+clc; clear;
+alpha = %pi/180;    // Acute angle of biprism, radian
+mu = 1.5;   // Refractive index of biprism
+lambda = 5500e-008;    // Wavelength of light used, cm
+y1 = 5;    // Distance of biprism from the source, cm
+y2 = 75;    // Distance of biprism from the screen, cm
+D = y1 + y2;    // Distance between slits and the screen, cm
+d = 2*(mu-1)*alpha*y1;  // Separation between the slits, cm
+b = lambda*D/d;  // Fringe width of the interfernce pattern due to biprism, cm
+
+printf("\nThe fringe width of the interfernce pattern due to biprism = %4.2e cm", b);
+
+// Result
+// The fringe width of the interfernce pattern due to biprism = 5.04e-02 cm 
diff --git a/1847/CH2/EX2.70/Ch02Ex70.sce b/1847/CH2/EX2.70/Ch02Ex70.sce
new file mode 100755
index 000000000..2ad10e75b
--- /dev/null
+++ b/1847/CH2/EX2.70/Ch02Ex70.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.70:: Page-2.57(2009)
+clc; clear;
+N = 250;        // Number of fringes crossing the field of view
+delta_x = 0.0595e-01;   // Displacement in movable mirror, cm
+// As N*lambda/2 = delta_x, solving for lambda
+lambda = 2*delta_x/N;      // Wavelength of light used, cm
+
+printf("\nThe wavelength of monochromatic light used = %4.0f ansgtrom", lambda/1e-008);
+
+// Result
+// The wavelength of monochromatic light used = 4760 ansgtrom 
+// Answer is given wrong in the textbook
diff --git a/1847/CH2/EX2.71/Ch02Ex71.sce b/1847/CH2/EX2.71/Ch02Ex71.sce
new file mode 100755
index 000000000..c84427e61
--- /dev/null
+++ b/1847/CH2/EX2.71/Ch02Ex71.sce
@@ -0,0 +1,11 @@
+// Scilab Code Ex2.71:: Page-2.58(2009)
+clc; clear;
+delta_x = 0.02559e-01;   // Displacement in movable mirror, cm
+lambda = 5890e-008;      // Wavelength of light used, cm
+// As N*lambda/2 = delta_x, solving for N
+N = 2*delta_x/lambda;       // Number of fringes crossing the field of view
+
+printf("\nThe number of fringes that passes across the cross wire of telescope = %2d", ceil(N));
+
+// Result
+// The number of fringes that passes across the cross wire of telescope = 87 
diff --git a/1847/CH2/EX2.72/Ch02Ex72.sce b/1847/CH2/EX2.72/Ch02Ex72.sce
new file mode 100755
index 000000000..0aa30aa44
--- /dev/null
+++ b/1847/CH2/EX2.72/Ch02Ex72.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.72:: Page-2.58(2009)
+clc; clear;
+lambda1 = 5890e-008;    // Wavelength corresponding to the D1 line, cm
+lambda2 = 5896e-008;    // Wavelength corresponding to the D2 line, cm
+delta_lambda = lambda2 - lambda1;   // Difference in the wavelengths, cm
+// As delta_lambda = lambda1*lambda2/(2*x), solving for x
+x = lambda1*lambda2/(2*(lambda2-lambda1));  // Distance between two successive positions of movable mirror
+
+printf("\nThe distance between two successive positions of movable mirror = %3.1e cm", x);
+
+// Result
+// The distance between two successive positions of movable mirror = 2.9e-002  
diff --git a/1847/CH2/EX2.73/Ch02Ex73.sce b/1847/CH2/EX2.73/Ch02Ex73.sce
new file mode 100755
index 000000000..5a4a6554d
--- /dev/null
+++ b/1847/CH2/EX2.73/Ch02Ex73.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.73:: Page-2.58(2009)
+clc; clear;
+N = 550;        // Number of fringes crossing the field of view
+lambda = 5500e-008;    // Wavelength of light used, cm
+mu = 1.5;       // Refractive index of the glass slab
+// As 2*(mu-1)*t = N*lambda, solving for t
+t = N*lambda/(2*(mu-1));       // Thickness of the transparent glass film
+
+printf("\nThe distance between two successive positions of movable mirror = %3.1e cm", t);
+
+// Result
+// The distance between two successive positions of movable mirror = 3.0e-002 cm 
diff --git a/1847/CH2/EX2.8/Ch02Ex8.sce b/1847/CH2/EX2.8/Ch02Ex8.sce
new file mode 100755
index 000000000..e9197dc4d
--- /dev/null
+++ b/1847/CH2/EX2.8/Ch02Ex8.sce
@@ -0,0 +1,15 @@
+// Scilab Code Ex2.8:: Page-2.11 (2009)
+clc; clear;
+mu = 1.5;   // Refractive index of biprism
+lambda = 5500e-008;    // Wavelength of light used, cm
+y1 = 5;    // Distance of biprism from the source, cm
+y2 = 95;    // Distance of biprism from the screen, cm
+D = y1 + y2;    // Distance between slits and the screen, cm
+b = 0.025;  // Fringe width of the interfernce pattern due to biprism, cm
+// As d = 2*(mu-1)*alpha*y1, solving for alpha
+alpha = lambda*D/(b*2*(mu-1)*y1)    // Angle of vertex of the biprism, radian
+
+printf("\nThe angle of vertex of the biprism = %3.1e rad", alpha);
+
+// Result
+// The angle of vertex of the biprism = 4.4e-02 rad 
diff --git a/1847/CH2/EX2.9/Ch02Ex9.sce b/1847/CH2/EX2.9/Ch02Ex9.sce
new file mode 100755
index 000000000..b444e31fa
--- /dev/null
+++ b/1847/CH2/EX2.9/Ch02Ex9.sce
@@ -0,0 +1,12 @@
+// Scilab Code Ex2.9:: Page-2.12 (2009)
+clc; clear;
+n1 = 69;    // Number of interference fringes obtained with yellow wavelength
+lambda1 = 5893e-008;    // Wavelength of yellow light used, cm
+lambda2 = 5461e-008;    // Wavelength of green light used, cm
+// As n*lambda = l*d/D = constant, therefore
+n2 = n1*lambda1/lambda2;    // Number of interference fringes for green wavelength
+
+printf("\nThe number of interference fringes for changed wavelength = %2d", ceil(n2));
+
+// Result
+// The number of interference fringes for changed wavelength = 75 
-- 
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