initial commit / add all books

88 files changed, 550 insertions, 0 deletions

diff --git a/1271/CH2/EX2.1/1.txt b/1271/CH2/EX2.1/1.txt
new file mode 100755
index 000000000..8b1842cf1
--- /dev/null
+++ b/1271/CH2/EX2.1/1.txt
@@ -0,0 +1,2 @@
+ Radius of 80th half period zone = 6.324555e-03 meter. 

+ Area of half period zone = 1.570796e-06 square meter.

diff --git a/1271/CH2/EX2.1/example2_1.sce b/1271/CH2/EX2.1/example2_1.sce
new file mode 100755
index 000000000..0e49f9ae9
--- /dev/null
+++ b/1271/CH2/EX2.1/example2_1.sce
@@ -0,0 +1,11 @@
+clc 
+// Given that
+lambda = 5e-7 // wavelength of light in meter
+d = 1 // distance of wavefront received on the screen from the opening in meter
+n = 80 // no. of half period zone
+// Sample Problem 1 on page no. 2.38
+printf("\n # PROBLEM 1 # \n")
+Rn = sqrt(n * lambda * d)// calculation for radius of nth half period zone
+A = %pi * d * lambda// calculation for area of half period zone
+printf("Standard formula used\n Rn = sqrt(n*d*lambda).\n A = pi*d*lambda.\n")
+printf("\n Radius of 80th half period zone = %f cm. \n Area of half period zone = %f square cm.",Rn*100,A*10000)
diff --git a/1271/CH2/EX2.10/10.txt b/1271/CH2/EX2.10/10.txt
new file mode 100755
index 000000000..43f1e0a97
--- /dev/null
+++ b/1271/CH2/EX2.10/10.txt
@@ -0,0 +1 @@
+ No. of zone of Fresnel = 2500.000000
\ No newline at end of file
diff --git a/1271/CH2/EX2.10/example2_10.sce b/1271/CH2/EX2.10/example2_10.sce
new file mode 100755
index 000000000..14d73440f
--- /dev/null
+++ b/1271/CH2/EX2.10/example2_10.sce
@@ -0,0 +1,12 @@
+clc 
+// Given that
+lambda = 4e-7 // wavelength of light in meter
+u = 0.2 // distance of object from zone plate in meter
+v = 0.2 // distance of brightest image from from zone plate in meter 
+r = 0.01 // radius in meter
+// Sample Problem 10 on page no. 2.41
+printf("\n # PROBLEM 10 # \n")
+f = (u * v) / (u + v) // calculation for focal length
+n = (r^2) / (f * lambda) // calculation for no. of zone of Fresnel
+printf("\n Standard formula used \n f = (u * v) / (u + v). \n n = (r^2) / (f * lambda).\n ")
+printf("\n No. of zone of Fresnel = %f",n)
diff --git a/1271/CH2/EX2.11/11.txt b/1271/CH2/EX2.11/11.txt
new file mode 100755
index 000000000..b72a69590
--- /dev/null
+++ b/1271/CH2/EX2.11/11.txt
@@ -0,0 +1,2 @@
+ 

+ Distance of first image from zone plate = 3.585144 meter 

diff --git a/1271/CH2/EX2.11/example2_11.sce b/1271/CH2/EX2.11/example2_11.sce
new file mode 100755
index 000000000..de4fa4334
--- /dev/null
+++ b/1271/CH2/EX2.11/example2_11.sce
@@ -0,0 +1,13 @@
+clc 
+// Given that
+lambda = 5.893e-7 // wavelength of light in meter
+d = 2.3e-3 // diameter of the central zone of zone plate in meter
+u = 6 // distance between point source from zone plate in meter
+// Sample Problem 11 on page no. 2.42
+printf("\n # PROBLEM 11 # \n")
+n = 1 // for central zone
+f = (d^2) / (4 * lambda * n) // calculation for focal length
+disp(f)
+v = (f * u) / (u - f)  // calculation for distance of first image from zone plate
+printf("\n Standard formula used \n f = (d^2) / (4 * lambda * n). \n v = (f * u) / (u - f). \n ")
+printf("\n Distance of first image from zone plate = %f meter ",v)
diff --git a/1271/CH2/EX2.12/12.txt b/1271/CH2/EX2.12/12.txt
new file mode 100755
index 000000000..776963297
--- /dev/null
+++ b/1271/CH2/EX2.12/12.txt
@@ -0,0 +1,2 @@
+ 

+ Principal focal length of zone plate = 2.000000 meter 

diff --git a/1271/CH2/EX2.12/example2_12.sce b/1271/CH2/EX2.12/example2_12.sce
new file mode 100755
index 000000000..338a2b1a0
--- /dev/null
+++ b/1271/CH2/EX2.12/example2_12.sce
@@ -0,0 +1,8 @@
+clc 
+// Given that
+R = 2 // radius of curvature in meter
+// Sample Problem 12 on page no. 2.42
+printf("\n # PROBLEM 12 # \n")
+f = R // calculation for principal focal length of zone plate
+printf("\n Standard formula used \n f = r^2 / lambda. \n r = sqrt(lambda*R). \n ")
+printf("\n Principal focal length of zone plate = %f meter ",f)
diff --git a/1271/CH2/EX2.13/13.txt b/1271/CH2/EX2.13/13.txt
new file mode 100755
index 000000000..ee8768ec2
--- /dev/null
+++ b/1271/CH2/EX2.13/13.txt
@@ -0,0 +1 @@
+ Angular spread of the central maxima = 0.067494 degree 
\ No newline at end of file
diff --git a/1271/CH2/EX2.13/example2_13.sce b/1271/CH2/EX2.13/example2_13.sce
new file mode 100755
index 000000000..16a6493bd
--- /dev/null
+++ b/1271/CH2/EX2.13/example2_13.sce
@@ -0,0 +1,11 @@
+clc 
+// Given that
+lambda = 5.89e-7 // wavelength of light in meter
+b = 1e-3 // slit-width in meter
+// Sample Problem 13 on page no. 2.42
+printf("\n # PROBLEM 13 # \n")
+m = 1 // for first minima
+theta = asin((m * lambda) / b) // calculation for angular spread of the central maxima in radian
+theta_ = theta * (180 / %pi) // calculation for angular spread of the central maxima in degree
+printf("\n Standard formula used \n theta = asin((m * lambda) / b).\n")
+printf("\n Angular spread of the central maxima = %f degree ",2 * theta_)
diff --git a/1271/CH2/EX2.14/14.txt b/1271/CH2/EX2.14/14.txt
new file mode 100755
index 000000000..7f8792ef1
--- /dev/null
+++ b/1271/CH2/EX2.14/14.txt
@@ -0,0 +1 @@
+ Wavelength of light = 6.166667e-07 meter. 
\ No newline at end of file
diff --git a/1271/CH2/EX2.14/example2_14.sce b/1271/CH2/EX2.14/example2_14.sce
new file mode 100755
index 000000000..540897172
--- /dev/null
+++ b/1271/CH2/EX2.14/example2_14.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+d = 1.2 // distance of screen from slit in meter
+x = 3.7e-3 // distance between first maxima to central maxima in meter
+b = 2e-4 // slit-width in meter
+// Sample Problem 14 on page no. 2.43
+printf("\n # PROBLEM 14 # \n")
+lambda = (x * b) / d // calculation for wavelength of light
+printf("\n Standard formula used \n lambda = (x * b) / d.\n")
+printf("\n Wavelength of light = %e meter. ",lambda)
diff --git a/1271/CH2/EX2.15/15.txt b/1271/CH2/EX2.15/15.txt
new file mode 100755
index 000000000..6d8681a44
--- /dev/null
+++ b/1271/CH2/EX2.15/15.txt
@@ -0,0 +1 @@
+Angular position of second and third minima = 30.000000 , 48.590378 degree respectively 
\ No newline at end of file
diff --git a/1271/CH2/EX2.15/example2_15.sce b/1271/CH2/EX2.15/example2_15.sce
new file mode 100755
index 000000000..fabda7663
--- /dev/null
+++ b/1271/CH2/EX2.15/example2_15.sce
@@ -0,0 +1,12 @@
+clc 
+// Given that
+lambda = 5.5e-7 // wavelength of light in meter
+b = 2.2e-6 // slit-width in meter
+// Sample Problem 15 on page no. 2.43
+printf("\n # PROBLEM 15 # \n")
+m2 = 2 // for second minima
+theta2 = asin((m2 * lambda) / b) * (180 / %pi) // calculation for angular position of second minima
+m3 = 3 // for third minima
+theta3 = asin((m3 * lambda) / b) * (180 / %pi) // calculation for angular position of third minima
+printf("\n Standard formula used \n theta = asin((m * lambda) / b) * (180 / pi). \n")
+printf("\n Angular position of second and third minima = %f , %f degree respectively ",theta2 ,theta3)
diff --git a/1271/CH2/EX2.16/16.txt b/1271/CH2/EX2.16/16.txt
new file mode 100755
index 000000000..31cec771a
--- /dev/null
+++ b/1271/CH2/EX2.16/16.txt
@@ -0,0 +1 @@
+ Half angular width of the central bright maxima = 29.395369 degree 
\ No newline at end of file
diff --git a/1271/CH2/EX2.16/example2_16.sce b/1271/CH2/EX2.16/example2_16.sce
new file mode 100755
index 000000000..f4e4db321
--- /dev/null
+++ b/1271/CH2/EX2.16/example2_16.sce
@@ -0,0 +1,11 @@
+clc 
+// Given that
+lambda = 5.89e-7 // wavelength of light in meter
+b = 1.2e-6 // slit-width in meter
+// Sample Problem 16 on page no. 2.44
+printf("\n # PROBLEM 16 # \n")
+m = 1 // for first minima
+theta = asin((m * lambda) / b) // calculation for half angular width of the central bright maxima in radian
+theta_ = theta * (180 / %pi) // calculation for half angular width of the central bright maxima in degree
+printf("\n Standard formula used \n theta = asin((m * lambda) / b).\n")
+printf("\n Half angular width of the central bright maxima = %f degree ",theta_)
diff --git a/1271/CH2/EX2.17/17.txt b/1271/CH2/EX2.17/17.txt
new file mode 100755
index 000000000..38700d4a9
--- /dev/null
+++ b/1271/CH2/EX2.17/17.txt
@@ -0,0 +1,2 @@
+ Slit width in first case = 1.000000e-06 meter. 

+ Slit width in second case = 5.000000e-07 meter

diff --git a/1271/CH2/EX2.17/example2_17.sce b/1271/CH2/EX2.17/example2_17.sce
new file mode 100755
index 000000000..d132632e5
--- /dev/null
+++ b/1271/CH2/EX2.17/example2_17.sce
@@ -0,0 +1,12 @@
+clc 
+// Given that
+lambda = 5e-7 // wavelength of light in meter
+theta = %pi / 6 // half angular width of central maximum in first case in radian
+theta_ = %pi / 2 // half angular width of central maximum in second case in radian
+// Sample Problem 17 on page no. 2.44
+printf("\n # PROBLEM 17 # \n")
+m = 1 // for first minima
+b1 = (lambda * m) / sin(theta) // calculation for slit width in first case
+b2 = (lambda * m) / sin(theta_) // calculation for slit width in second case
+printf("\n Standard formula used \n b = (lambda * m) / sin(theta). \n")
+printf("\n Slit width in first case = %e meter. \n Slit width in second case = %e meter",b1,b2)
diff --git a/1271/CH2/EX2.18/18.txt b/1271/CH2/EX2.18/18.txt
new file mode 100755
index 000000000..f561ac65d
--- /dev/null
+++ b/1271/CH2/EX2.18/18.txt
@@ -0,0 +1 @@
+Angular spread = 0.337474 degree
\ No newline at end of file
diff --git a/1271/CH2/EX2.18/example2_18.sce b/1271/CH2/EX2.18/example2_18.sce
new file mode 100755
index 000000000..5f6edc480
--- /dev/null
+++ b/1271/CH2/EX2.18/example2_18.sce
@@ -0,0 +1,11 @@
+clc 
+// Given that
+lambda = 5.89e-7 // wavelength of light in meter
+d = 1 // distance of screen from slit in meter
+b = 1e-4 // slit-width in meter
+// Sample Problem 18 on page no. 2.44
+printf("\n # PROBLEM 18 # \n")
+theta = (asin(lambda / b)) * (180 / %pi) // calculation for angular spread
+x = (2 * d * lambda) / b// calculation for linear width
+printf("\n Standard formula used \n theta = (asin(lambda / b)) * (180 / pi). \n x = (2 * d * lambda) / b. \n")
+printf("\n Angular spread = %f degree\n Linear width = %e meter ",theta,x)
diff --git a/1271/CH2/EX2.2/2.txt b/1271/CH2/EX2.2/2.txt
new file mode 100755
index 000000000..c44ea7636
--- /dev/null
+++ b/1271/CH2/EX2.2/2.txt
@@ -0,0 +1 @@
+ Radius of  half period zone = 6.000000e-04 meter 
\ No newline at end of file
diff --git a/1271/CH2/EX2.2/example2_2.sce b/1271/CH2/EX2.2/example2_2.sce
new file mode 100755
index 000000000..a5f99e744
--- /dev/null
+++ b/1271/CH2/EX2.2/example2_2.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+lambda = 6e-7 // wavelength of light in meter
+f = 0.6 // focal length of convex lens in meter
+n = 1 // no. of half period zone
+// Sample Problem 2 on page no. 2.38
+printf("\n # PROBLEM 2 # \n")
+Rn = sqrt(n * lambda * f)// calculation for radius of half period zone
+printf("Standard formula used \n f = Rn^2/(n*lambda)\n")
+printf("\n Radius of  half period zone = %f mm ",Rn*1000)
diff --git a/1271/CH2/EX2.20/20.txt b/1271/CH2/EX2.20/20.txt
new file mode 100755
index 000000000..2d169d964
--- /dev/null
+++ b/1271/CH2/EX2.20/20.txt
@@ -0,0 +1 @@
+ Angular width of the central maxima = 60.000000 degree 
\ No newline at end of file
diff --git a/1271/CH2/EX2.20/example2_20.sce b/1271/CH2/EX2.20/example2_20.sce
new file mode 100755
index 000000000..1dc43215d
--- /dev/null
+++ b/1271/CH2/EX2.20/example2_20.sce
@@ -0,0 +1,11 @@
+clc 
+// Given that
+lambda = 6e-7 // wavelength of light in meter
+b = 1.2e-6 // slit-width in meter
+// Sample Problem 20 on page no. 2.46
+printf("\n # PROBLEM 20 # \n")
+m = 1 // for first minima
+theta = asin((m * lambda) / b) // calculation for angular width of the central maxima in radian
+theta_ = theta * (180 / %pi) // calculation for angular width of the central maxima in degree
+printf("\n Standard formula used \n theta = asin((m * lambda) / b). \n")
+printf("\n Angular width of the central maxima = %f degree ",2 * theta_)
diff --git a/1271/CH2/EX2.21/21.txt b/1271/CH2/EX2.21/21.txt
new file mode 100755
index 000000000..07d0bf9b0
--- /dev/null
+++ b/1271/CH2/EX2.21/21.txt
@@ -0,0 +1 @@
+Separation of dark band = 1.956000e-05 meter.
\ No newline at end of file
diff --git a/1271/CH2/EX2.21/example2_21.sce b/1271/CH2/EX2.21/example2_21.sce
new file mode 100755
index 000000000..46fa88d5f
--- /dev/null
+++ b/1271/CH2/EX2.21/example2_21.sce
@@ -0,0 +1,14 @@
+clc 
+// Given that
+lambda = 4.890e-7 // wavelength of light in meter
+b = 5e-3 // slit-width in meter
+f = 0.4 // focal-length of convex lens in meter
+// Sample Problem 21 on page no. 2.46
+printf("\n # PROBLEM 21 # \n")
+m = 1 // for first dark fringe
+x = (f * m * lambda) / b  
+n = 1 // for first secondary maxima
+x_ = ((2 * n + 1) * lambda * f) / (2 * b) 
+delta_x = x_ - x // calculation for separation of dark band 
+printf("\n Standard formula used \n x = (f * m * lambda) / b . \n delta_x = x_ - x. \n")
+printf("\n Separation of dark band = %e meter.",delta_x)
diff --git a/1271/CH2/EX2.22/22.txt b/1271/CH2/EX2.22/22.txt
new file mode 100755
index 000000000..2ef95074e
--- /dev/null
+++ b/1271/CH2/EX2.22/22.txt
@@ -0,0 +1 @@
+Separation of dark band on either side of the central maximum = 2.357200e-03 meter
\ No newline at end of file
diff --git a/1271/CH2/EX2.22/example2_22.sce b/1271/CH2/EX2.22/example2_22.sce
new file mode 100755
index 000000000..d90ebcb7f
--- /dev/null
+++ b/1271/CH2/EX2.22/example2_22.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+lambda = 5.893e-7 // wavelength of light in meter
+b = 5e-4 // slit-width in meter
+f = 1 // focal length of convex lens in meter
+// Sample Problem 22 on page no. 2.47
+printf("\n # PROBLEM 22 # \n")
+x = (2 * lambda * f) / b // calculation for Separation of dark band on either side of the cenral maximum
+printf("Standard formula used \n. \n")
+printf("\n Separation of dark band on either side of the central maximum = %e meter",x)
diff --git a/1271/CH2/EX2.23/23.txt b/1271/CH2/EX2.23/23.txt
new file mode 100755
index 000000000..ddca7d17f
--- /dev/null
+++ b/1271/CH2/EX2.23/23.txt
@@ -0,0 +1 @@
+ Missing orders = 6,12,18,......
\ No newline at end of file
diff --git a/1271/CH2/EX2.23/example2_23.sce b/1271/CH2/EX2.23/example2_23.sce
new file mode 100755
index 000000000..9236a9545
--- /dev/null
+++ b/1271/CH2/EX2.23/example2_23.sce
@@ -0,0 +1,15 @@
+clc 
+// Given that
+d = 4e-4 // separation between slits in meter
+b = 8e-5 // slit-width in meter
+// Sample Problem 23 on page no. 2.47
+printf("\n # PROBLEM 23 # \n")
+r = (b + d) / b // calculation for ratio of n with m
+m1 = 1
+n1 = r * m1 // calculation for Missing orders 
+m2 = 2
+n2 = r * m2 // calculation for Missing orders 
+m3 = 3
+n3 = r * m3 // calculation for Missing orders 
+printf("\n Standard formula used \n r = (b + d) / b. \n n = r * m. \n")
+printf("\n Missing orders = %d,%d,%d,......",n1,n2,n3)
diff --git a/1271/CH2/EX2.24/24.txt b/1271/CH2/EX2.24/24.txt
new file mode 100755
index 000000000..631879e48
--- /dev/null
+++ b/1271/CH2/EX2.24/24.txt
@@ -0,0 +1,2 @@
+ Wavelength of light = 6.250000e-07 

+ Missing order = 3,6,9....

diff --git a/1271/CH2/EX2.24/example2_24.sce b/1271/CH2/EX2.24/example2_24.sce
new file mode 100755
index 000000000..2ba42b6f8
--- /dev/null
+++ b/1271/CH2/EX2.24/example2_24.sce
@@ -0,0 +1,18 @@
+clc 
+// Given that
+d = 4e-4 // separation between slits in meter
+b = 2e-4 // slit-width in meter
+fringe_width = 2.5e-3 // fringe width in meter
+D = 1.6 // distance between screen and slits
+// Sample Problem 24 on page no. 2.47
+printf("\n # PROBLEM 24 # \n")
+lambda = (fringe_width * d) / D // calculation for wavelength of light
+r = (b + d) / b // calculation for ratio of n with m
+m1 = 1
+n1 = r * m1 // calculation for missing order
+m2 = 2
+n2 = r * m2 // calculation for missing order
+m3 = 3
+n3 = r * m3 // calculation for missing order
+printf("\n Standard formula used \n lambda = (fringe_width * d) / D. \n r = (b + d) / b. \n n = r * m. \n")
+printf("\n Wavelength of light = %e meter. \n Missing order = %d,%d,%d....",lambda,n1,n2,n3)
diff --git a/1271/CH2/EX2.25/25.txt b/1271/CH2/EX2.25/25.txt
new file mode 100755
index 000000000..d1454b5b5
--- /dev/null
+++ b/1271/CH2/EX2.25/25.txt
@@ -0,0 +1 @@
+ Wavelength of light = 5.882353e-07 meter. 
\ No newline at end of file
diff --git a/1271/CH2/EX2.25/example2_25.sce b/1271/CH2/EX2.25/example2_25.sce
new file mode 100755
index 000000000..20a4d836b
--- /dev/null
+++ b/1271/CH2/EX2.25/example2_25.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+N = 425000 // no. of lines in plane transmission grating per meter
+theta = %pi / 6 // angle at which second order spectral line is observed in radian
+n = 2 // order of spectral line
+// Sample Problem 25 on page no. 2.48
+printf("\n # PROBLEM 25 # \n")
+lambda = sin(theta) / (2 * N) // calculation for wavelength of light
+printf("\n Standard formula used \n lambda = sin(theta) / (2 * N). \n")
+printf("\n Wavelength of light = %e meter. ",lambda)
diff --git a/1271/CH2/EX2.26/26.txt b/1271/CH2/EX2.26/26.txt
new file mode 100755
index 000000000..4152e9fbe
--- /dev/null
+++ b/1271/CH2/EX2.26/26.txt
@@ -0,0 +1 @@
+wavelength of light = 5.000000e-07 meter. 
\ No newline at end of file
diff --git a/1271/CH2/EX2.26/example2_26.sce b/1271/CH2/EX2.26/example2_26.sce
new file mode 100755
index 000000000..99445c266
--- /dev/null
+++ b/1271/CH2/EX2.26/example2_26.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+N = 500000 // no. of lines in plane transmission grating per meter
+theta = %pi / 6 // angle at which second order spectral line is observed in radian
+n = 2 // order of spectral line
+// Sample Problem 26 on page no. 2.48
+printf("\n # PROBLEM 26 # \n")
+lambda = sin(theta) / (2 * N) // calculation for wavelength of light
+printf("\n Standard formula used \n lambda = sin(theta) / (2 * N). \n ")
+printf("\n wavelength of light = %e meter. ",lambda)
diff --git a/1271/CH2/EX2.27/27.txt b/1271/CH2/EX2.27/27.txt
new file mode 100755
index 000000000..761d1f89e
--- /dev/null
+++ b/1271/CH2/EX2.27/27.txt
@@ -0,0 +1,3 @@
+

+

+ Wavelength of light in first case = 4096 A 
\ No newline at end of file
diff --git a/1271/CH2/EX2.27/example2_27.sce b/1271/CH2/EX2.27/example2_27.sce
new file mode 100755
index 000000000..18b36ba6c
--- /dev/null
+++ b/1271/CH2/EX2.27/example2_27.sce
@@ -0,0 +1,11 @@
+
+clc 
+// Given that
+lambda2 = 5.461e-7 // wavelength of  light in second case in meter
+n1 = 4 // no. of order in first case
+n2 = 3 // no. of order in second case 
+// Sample Problem 27 on page no. 2.48
+printf("\n # PROBLEM 27 # \n")
+lambda1 = (n2 * lambda2) / n1 // calculation for Wavelength of light in first case
+printf("Standard formula used \n lambda1 = (n2 * lambda2) / n1. \n")
+printf("\n Wavelength of light in first case = %d A",ceil(lambda1*1e10))
diff --git a/1271/CH2/EX2.28/28.txt b/1271/CH2/EX2.28/28.txt
new file mode 100755
index 000000000..ba45cdaa6
--- /dev/null
+++ b/1271/CH2/EX2.28/28.txt
@@ -0,0 +1 @@
+ No. of lines in per cm = 5000.000000 
\ No newline at end of file
diff --git a/1271/CH2/EX2.28/example2_28.sce b/1271/CH2/EX2.28/example2_28.sce
new file mode 100755
index 000000000..dd8157337
--- /dev/null
+++ b/1271/CH2/EX2.28/example2_28.sce
@@ -0,0 +1,11 @@
+clc 
+// Given that
+lambda = 5e-7 // wavelength of light in meter
+theta = %pi / 6 // angle at which second order spectral line is observed in radian
+n = 2 // order of spectral line
+// Sample Problem 28 on page no. 2.49
+printf("\n # PROBLEM 28 # \n")
+k = (n * lambda) / sin(theta) // calculation for (b+d)
+N = 1 / k // calculation for no. of lines in per cm
+printf("\n Standard formula used \n b+d = (n * lambda) / sin(theta). \n N = 1 / k. \n ")
+printf("\n No. of lines per cm = %f ",N / 100)
diff --git a/1271/CH2/EX2.29/29.txt b/1271/CH2/EX2.29/29.txt
new file mode 100755
index 000000000..0f5044287
--- /dev/null
+++ b/1271/CH2/EX2.29/29.txt
@@ -0,0 +1 @@
+ Angle of separation = 0.269269 degree
\ No newline at end of file
diff --git a/1271/CH2/EX2.29/example2_29.sce b/1271/CH2/EX2.29/example2_29.sce
new file mode 100755
index 000000000..bbdcd7435
--- /dev/null
+++ b/1271/CH2/EX2.29/example2_29.sce
@@ -0,0 +1,14 @@
+clc 
+// Given that
+lambda1 = 5.048e-7 // wavelength of light in first case in meter
+lambda2 = 5.016e-7 // wavelength of light in second case in meter
+n = 2 // no. of order in first case
+N = 15000 // no. of lines in grating per inch  
+// Sample Problem 29 on page no. 2.49
+printf("\n # PROBLEM 29 # \n")
+k = 2.54 / 1500000 // in meter
+theta1 = asin(n * lambda1 / k) * (180 / %pi) // calculation for angle in first case
+theta2 = asin(n * lambda2 / k) * (180 / %pi) // calculation for angle in second case
+delta_theta = theta1 - theta2 // calculation for angle of separation
+printf("\n Standard formula used \n theta = asin(n * lambda / k) * (180 / pi). \n")
+printf("\n Angle of separation = %f degree",delta_theta)
diff --git a/1271/CH2/EX2.3/3.txt b/1271/CH2/EX2.3/3.txt
new file mode 100755
index 000000000..9242d998f
--- /dev/null
+++ b/1271/CH2/EX2.3/3.txt
@@ -0,0 +1,2 @@
+

+ Radius of 80th half period zone = 3.872983e-04 meter 
\ No newline at end of file
diff --git a/1271/CH2/EX2.3/example2_3.sce b/1271/CH2/EX2.3/example2_3.sce
new file mode 100755
index 000000000..2588c02ba
--- /dev/null
+++ b/1271/CH2/EX2.3/example2_3.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+lambda = 5e-7 // wavelength of light in meter
+d = 0.3 // distance of wavefront received on screen from the opening in meter
+// Sample Problem 3 on page no. 2.38
+printf("\n # PROBLEM 3 # \n")
+n = 1 // no. of half period zone
+Rn = sqrt(n * lambda * d) // because at maxima intensity is four time the individual intensity of light
+printf("Standard formula used \n r = sqrt(d*lambda)\n")
+printf("\n Radius of 80th half period zone = %f mm. ",Rn*1000)
diff --git a/1271/CH2/EX2.30/30.txt b/1271/CH2/EX2.30/30.txt
new file mode 100755
index 000000000..a37f88f31
--- /dev/null
+++ b/1271/CH2/EX2.30/30.txt
@@ -0,0 +1 @@
+ Angle of separation = 0.058345 degree
\ No newline at end of file
diff --git a/1271/CH2/EX2.30/example2_30.sce b/1271/CH2/EX2.30/example2_30.sce
new file mode 100755
index 000000000..109f57d16
--- /dev/null
+++ b/1271/CH2/EX2.30/example2_30.sce
@@ -0,0 +1,14 @@
+clc 
+// Given that
+lambda1 = 5.89e-7 // wavelength of  light in first case in meter
+lambda2 = 5.896e-7 // wavelength of  light in second case in meter
+n = 2 // no. of order in first case
+N = 600000 // no. of lines in grating per meter  
+// Sample Problem 30 on page no. 2.50
+printf("\n # PROBLEM 30 # \n")
+k = 1 / N // in meter
+theta1 = asin(n * lambda1 / k) * (180 / %pi) // calculation for angle in first case
+theta2 = asin(n * lambda2 / k) * (180 / %pi) // calculation for angle in second case
+delta_theta = theta2 - theta1 // calculation for angle of separation
+printf("\n Standard formula used \n theta1 = asin(n * lambda1 / k) * (180 / pi). \n ")
+printf("\n Angle of separation = %f degree",delta_theta)
diff --git a/1271/CH2/EX2.31/31.txt b/1271/CH2/EX2.31/31.txt
new file mode 100755
index 000000000..3e4f221f5
--- /dev/null
+++ b/1271/CH2/EX2.31/31.txt
@@ -0,0 +1 @@
+ No. of lines per cm = 3086 
\ No newline at end of file
diff --git a/1271/CH2/EX2.31/example2_31.sce b/1271/CH2/EX2.31/example2_31.sce
new file mode 100755
index 000000000..2ba8da3db
--- /dev/null
+++ b/1271/CH2/EX2.31/example2_31.sce
@@ -0,0 +1,11 @@
+clc 
+// Given that
+lambda1 = 5.4e-7 // wavelength of light for nth order in meter
+lambda2 = 4.05e-7 // wavelength of light for (n+1)th order in meter 
+theta = %pi / 6 // angle of diffraction in radian 
+// Sample Problem 31 on page no. 2.50
+printf("\n # PROBLEM 31 # \n")
+k = (lambda1 * lambda2) / ((lambda1 - lambda2) * sin(theta)) // calculation for b+d
+N = (1 / k) * (0.01) // calculation for no. of lines per cm
+printf("\n Standard formula used \n b+d = (lambda1 * lambda2) / ((lambda1 - lambda2) * sin(theta)). \n N = (1 / k) * (0.01). \n")
+printf("\n No. of lines per cm = %d ",N)
diff --git a/1271/CH2/EX2.32/32.txt b/1271/CH2/EX2.32/32.txt
new file mode 100755
index 000000000..312b2c93f
--- /dev/null
+++ b/1271/CH2/EX2.32/32.txt
@@ -0,0 +1 @@
+ Difference in two wavelength = 8.660254e-09 meter 
\ No newline at end of file
diff --git a/1271/CH2/EX2.32/example2_32.sce b/1271/CH2/EX2.32/example2_32.sce
new file mode 100755
index 000000000..1a0d3125c
--- /dev/null
+++ b/1271/CH2/EX2.32/example2_32.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+d_theta = 0.01 // angular separation between two wavelengths in radian 
+theta = %pi / 6 // angle of diffraction in radian 
+lambda = 5e-7 // wavelength of light in meter
+// Sample Problem 32 on page no. 2.51
+printf("\n # PROBLEM 32 # \n")
+d_lambda = (lambda * cos(theta) * d_theta) / sin(theta) // calculation for difference in two waveligth
+printf("Standard formula used \n d_lambda = (lambda * cos(theta) * d_theta) / sin(theta). \n\n")
+printf("\n Difference in two wavelength = %e meter ",d_lambda)
diff --git a/1271/CH2/EX2.33/33.txt b/1271/CH2/EX2.33/33.txt
new file mode 100755
index 000000000..f91f96d69
--- /dev/null
+++ b/1271/CH2/EX2.33/33.txt
@@ -0,0 +1 @@
+ Order of spectrum = 19
\ No newline at end of file
diff --git a/1271/CH2/EX2.33/example2_33.sce b/1271/CH2/EX2.33/example2_33.sce
new file mode 100755
index 000000000..aba41f019
--- /dev/null
+++ b/1271/CH2/EX2.33/example2_33.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+N = 2620 // no. of lines in plane transmission grating per inch
+lambda = 5e-7 // wavelength of incident radiation in meter
+// Sample Problem 33 on page no. 2.51
+printf("\n # PROBLEM 33 # \n")
+k = 2.54 / N * 1 / 100 // calculation for b+d in meter
+n = k / lambda // calculation for order of spectrum
+printf("\n Standard formula used \n n = k / lambda ")
+printf("\n Order of spectrum = %d",n)
diff --git a/1271/CH2/EX2.34/34.txt b/1271/CH2/EX2.34/34.txt
new file mode 100755
index 000000000..a57e43560
--- /dev/null
+++ b/1271/CH2/EX2.34/34.txt
@@ -0,0 +1 @@
+ Order of spectrum = 4
\ No newline at end of file
diff --git a/1271/CH2/EX2.34/example2_34.sce b/1271/CH2/EX2.34/example2_34.sce
new file mode 100755
index 000000000..036fe2859
--- /dev/null
+++ b/1271/CH2/EX2.34/example2_34.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+N = 500000 // no. of lines in plane transmission grating per meter
+lambda = 5e-7 // wavelength of incident radiation in meter
+// Sample Problem 34 on page no. 2.51
+printf("\n # PROBLEM 34 # \n")
+k = 1 / N // calculation for b+d in meter
+n = k / lambda // calculation for order of spectrum 
+printf("\n Standard formula used \n k = 1 / N. \n n = k / lambda. \n")
+printf("\n Order of spectrum = %d",n)
diff --git a/1271/CH2/EX2.35/35.txt b/1271/CH2/EX2.35/35.txt
new file mode 100755
index 000000000..970d0441e
--- /dev/null
+++ b/1271/CH2/EX2.35/35.txt
@@ -0,0 +1 @@
+Observed order = 6,3
\ No newline at end of file
diff --git a/1271/CH2/EX2.35/example2_35.sce b/1271/CH2/EX2.35/example2_35.sce
new file mode 100755
index 000000000..202cced25
--- /dev/null
+++ b/1271/CH2/EX2.35/example2_35.sce
@@ -0,0 +1,11 @@
+clc 
+// Given that
+N = 400000 // no. of lines in plane transmission grating per meter
+lambda1 = 4e-7 // wavelength of light in first case in meter
+lambda2 = 7e-7 // wavelength of light in second case in meter
+// Sample Problem 35 on page no. 2.52
+printf("\n # PROBLEM 35 # \n")
+n1 = 1 / (N * lambda1) // calculation for Observed order in first case
+n2 = 1 / (N * lambda2) // calculation for Observed order in second case
+printf("Standard formula used \n n = 1 / (N * lambda). \n")
+printf("\n Observed order = %d,%d",n1,n2)
diff --git a/1271/CH2/EX2.36/36.txt b/1271/CH2/EX2.36/36.txt
new file mode 100755
index 000000000..0176f4eac
--- /dev/null
+++ b/1271/CH2/EX2.36/36.txt
@@ -0,0 +1 @@
+ Dispersive power = 1.897367e+06 rad/m
\ No newline at end of file
diff --git a/1271/CH2/EX2.36/example2_36.sce b/1271/CH2/EX2.36/example2_36.sce
new file mode 100755
index 000000000..7c102fb46
--- /dev/null
+++ b/1271/CH2/EX2.36/example2_36.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+N = 400000 // no. of lines in grating per meter
+lambda = 5e-7 // wavelength of incident radiation in meter
+n = 3 // no. of order
+// Sample Problem 36 on page no. 2.52
+printf("\n # PROBLEM 36 # \n")
+p = (n * N) / (sqrt(1 - (N * n * lambda)))// dispersive power (p) = d(theta)/d(lambda)
+printf("\n Standard formula used \n p = (n * N) / (sqrt(1 - (N * n * lambda))). \n")
+printf("\n Dispersive power = %e rad/m",p)
diff --git a/1271/CH2/EX2.37/37.txt b/1271/CH2/EX2.37/37.txt
new file mode 100755
index 000000000..a16f7723a
--- /dev/null
+++ b/1271/CH2/EX2.37/37.txt
@@ -0,0 +1 @@
+ Minimum no. of lines in grating = 490.833333
\ No newline at end of file
diff --git a/1271/CH2/EX2.37/example2_37.sce b/1271/CH2/EX2.37/example2_37.sce
new file mode 100755
index 000000000..43f6a8f58
--- /dev/null
+++ b/1271/CH2/EX2.37/example2_37.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+n = 2 // no. of order
+lambda1 = 5.89e-7 // wavelength of light in first case in meter
+lambda2 = 5.896e-7 // wavelength of light in second case in meter
+// Sample Problem 37 on page no. 2.52
+printf("\n # PROBLEM 37 # \n")
+N = lambda1 / (n * (lambda2 - lambda1)) // calculation for minimum no. of lines in grating 
+printf("\n Standard formula used \n N = lambda1 / (n * (lambda2 - lambda1)). \n") 
+printf("\n Minimum no. of lines in grating = %f,",N)
diff --git a/1271/CH2/EX2.38/38.txt b/1271/CH2/EX2.38/38.txt
new file mode 100755
index 000000000..8dbc92116
--- /dev/null
+++ b/1271/CH2/EX2.38/38.txt
@@ -0,0 +1 @@
+Minimum no. of lines in grating = 981.666667,
\ No newline at end of file
diff --git a/1271/CH2/EX2.38/example2_38.sce b/1271/CH2/EX2.38/example2_38.sce
new file mode 100755
index 000000000..aa310aa0d
--- /dev/null
+++ b/1271/CH2/EX2.38/example2_38.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+n = 1 // no. of order
+lambda1 = 5.89e-7 // wavelength of light in first case in meter
+lambda2 = 5.896e-7 // wavelength of light in second case in meter
+// Sample Problem 38 on page no. 2.53
+printf("\n # PROBLEM 38 # \n")
+N = lambda1 / (n * (lambda2 - lambda1)) // calculation for minimum no. of lines in grating
+printf("Standard formula used \n lambda/d(lambda)=n*N. \n")
+printf("\n Minimum no. of lines in grating = %f,",N)
diff --git a/1271/CH2/EX2.39/39.txt b/1271/CH2/EX2.39/39.txt
new file mode 100755
index 000000000..88e5b152d
--- /dev/null
+++ b/1271/CH2/EX2.39/39.txt
@@ -0,0 +1,2 @@
+ Grating space = 3.535800e-06 meter. 

+ Total width of ruled surface = 1.156992e-03 meter. 

diff --git a/1271/CH2/EX2.39/example2_39.sce b/1271/CH2/EX2.39/example2_39.sce
new file mode 100755
index 000000000..b12fe647b
--- /dev/null
+++ b/1271/CH2/EX2.39/example2_39.sce
@@ -0,0 +1,13 @@
+clc 
+// Given that
+n = 3 // no. of order
+theta = %pi / 6 // view angle of third order in radian
+lambda1 = 5.89e-7 // min. wavelength of light in meter
+lambda2 = 5.896e-7 // max.wavelength of light in meter
+// Sample Problem 39 on page no. 2.53
+printf("\n # PROBLEM 39 # \n")
+mean_lambda = (lambda1 + lambda2) / 2 // calculation for mean wavelength
+s = (n * mean_lambda) / sin(theta) // calculation for grating space b+d
+N = lambda1 / (n * (lambda2 - lambda1)) // calculation for minimum no. of lines in grating
+printf("\n Standard formula used \n mean_lambda = (lambda1 + lambda2) / 2. \n s = (n * mean_lambda) / sin(theta). \n N = lambda1 / (n * (lambda2 - lambda1)). \n")
+printf("\n Grating space = %e meter. \n Total width of ruled surface = %e meter. ",s,s * N)
diff --git a/1271/CH2/EX2.4/4.txt b/1271/CH2/EX2.4/4.txt
new file mode 100755
index 000000000..b527c2ffb
--- /dev/null
+++ b/1271/CH2/EX2.4/4.txt
@@ -0,0 +1,2 @@
+ No. of half period zone in first case = 13 

+ no. of half period zone in second case = 1333 

diff --git a/1271/CH2/EX2.4/example2_4.sce b/1271/CH2/EX2.4/example2_4.sce
new file mode 100755
index 000000000..176d40951
--- /dev/null
+++ b/1271/CH2/EX2.4/example2_4.sce
@@ -0,0 +1,12 @@
+clc 
+// Given that
+lambda = 6e-7 // wavelength of light in meter
+d = 0.5 // distance of observation point from circular opening in meter
+r1 = 2e-3 // radius of circular opening in first case in meter
+r2 = 2e-2 // radius of circular opening in second case in meter 
+// Sample Problem 4 on page no. 2.39
+printf("\n # PROBLEM 4 # \n")
+n1 = (r1^2) / (d * lambda) // calculation for no. of half period zone in first case 
+n2 = (r2^2) / (d * lambda) // calculation for no. of half period zone in second case
+printf("\n Standard formula used \n n = (r^2) / (d * lambda) \n")
+printf("\n No. of half period zone in first case = %d \n no. of half period zone in second case = %d ",n1,n2)
diff --git a/1271/CH2/EX2.40/40.txt b/1271/CH2/EX2.40/40.txt
new file mode 100755
index 000000000..9bd004606
--- /dev/null
+++ b/1271/CH2/EX2.40/40.txt
@@ -0,0 +1 @@
+ The separation of two points on moon = 50.996000 meter
\ No newline at end of file
diff --git a/1271/CH2/EX2.40/example2_40.sce b/1271/CH2/EX2.40/example2_40.sce
new file mode 100755
index 000000000..e31f566e8
--- /dev/null
+++ b/1271/CH2/EX2.40/example2_40.sce
@@ -0,0 +1,11 @@
+clc 
+// Given that
+lambda = 5.5e-7 // wavelength of light in meter
+a = 5 // diameter of objective lens of telescope in meter
+R = 3.8e8 // distance of moon in meter
+// Sample Problem 40 on page no. 2.53
+printf("\n # PROBLEM 40 # \n")
+theta = (1.22 * lambda) / a // calculation for angle 
+x = (R * theta) // calculation for the separation of two points on moon
+printf("\n Standard formula used \n theta = (1.22 * lambda) / a. \n x = (R * theta). \n")
+printf("\n The separation of two points on moon = %f meter",x)
diff --git a/1271/CH2/EX2.41/41.txt b/1271/CH2/EX2.41/41.txt
new file mode 100755
index 000000000..2278f2531
--- /dev/null
+++ b/1271/CH2/EX2.41/41.txt
@@ -0,0 +1 @@
+ Diameter of telescope objective = 0.034950 meter
\ No newline at end of file
diff --git a/1271/CH2/EX2.41/example2_41.sce b/1271/CH2/EX2.41/example2_41.sce
new file mode 100755
index 000000000..a23923406
--- /dev/null
+++ b/1271/CH2/EX2.41/example2_41.sce
@@ -0,0 +1,9 @@
+clc 
+// Given that
+lambda = 5e-7 // wavelength of light in meter
+theta = (1e-3) * (%pi / 180) // separation angle of stars in radian
+// Sample Problem 41 on page no. 2.54
+printf("\n # PROBLEM 41 # \n")
+a = (1.22 * lambda) / theta // calculation for diameter of telescope objective
+printf("\n Standard formula used \n a = (1.22 * lambda) / theta. \n")
+printf("\n Diameter of telescope objective = %f meter",a)
diff --git a/1271/CH2/EX2.42/42.txt b/1271/CH2/EX2.42/42.txt
new file mode 100755
index 000000000..215c1d1dc
--- /dev/null
+++ b/1271/CH2/EX2.42/42.txt
@@ -0,0 +1 @@
+ Diameter of telescope objective = 0.300000 meter
\ No newline at end of file
diff --git a/1271/CH2/EX2.42/example2_42.sce b/1271/CH2/EX2.42/example2_42.sce
new file mode 100755
index 000000000..437bb3e15
--- /dev/null
+++ b/1271/CH2/EX2.42/example2_42.sce
@@ -0,0 +1,9 @@
+clc 
+// Given that
+lambda = 6e-7 // wavelength of light in meter
+theta = 2.44e-6 // separation angle of stars in radian
+// Sample Problem 42 on page no. 2.54
+printf("\n # PROBLEM 42 # \n")
+a = (1.22 * lambda) / theta // calculation for diameter of telescope objective
+printf("\n Standard formula used \n a = (1.22 * lambda) / theta. \n")
+printf("\n Diameter of telescope objective = %f meter",a)
diff --git a/1271/CH2/EX2.43/43.txt b/1271/CH2/EX2.43/43.txt
new file mode 100755
index 000000000..b1289cd2b
--- /dev/null
+++ b/1271/CH2/EX2.43/43.txt
@@ -0,0 +1 @@
+ Max. distance of pin holes from microscope = 8.941878 meter
\ No newline at end of file
diff --git a/1271/CH2/EX2.43/example2_43.sce b/1271/CH2/EX2.43/example2_43.sce
new file mode 100755
index 000000000..c01fe14fe
--- /dev/null
+++ b/1271/CH2/EX2.43/example2_43.sce
@@ -0,0 +1,11 @@
+clc 
+// Given that
+lambda = 5.5e-7 // wavelength of light in meter
+a = 0.004 // diameter of objective lens of telescope in meter
+x = 1.5e-3 // distance between two pin holes in meter
+// Sample Problem 43 on page no. 2.54
+printf("\n # PROBLEM 43 # \n")
+theta = (1.22 * lambda) / a // calculation for angle  
+R = x / theta // calculation for max. distance of pin holes from microscope
+printf("\n Standard formula used \n theta = (1.22 * lambda) / a. \n R = x / theta. \n ")
+printf("\n Max. distance of pin holes from microscope = %f meter",R)
diff --git a/1271/CH2/EX2.44/44.txt b/1271/CH2/EX2.44/44.txt
new file mode 100755
index 000000000..3b2074903
--- /dev/null
+++ b/1271/CH2/EX2.44/44.txt
@@ -0,0 +1 @@
+ The resolving limit of microscope = 6.710000e-07 meter
\ No newline at end of file
diff --git a/1271/CH2/EX2.44/example2_44.sce b/1271/CH2/EX2.44/example2_44.sce
new file mode 100755
index 000000000..af7da1e7e
--- /dev/null
+++ b/1271/CH2/EX2.44/example2_44.sce
@@ -0,0 +1,9 @@
+clc 
+// Given that
+lambda = 5.5e-7 // wavelength of light in meter
+theta = %pi / 6 // semi-angle of cone in radian
+// Sample Problem 44 on page no. 2.55
+printf("\n # PROBLEM 44 # \n")
+d = (1.22 * lambda) / (2 * sin(theta)) // calculation for the resolving limit of microscope 
+printf("Standard formula used \n d*sin(theta)= 1.22*lamda. \n")
+printf("\n The resolving limit of microscope = %e meter",d)
diff --git a/1271/CH2/EX2.45/45.txt b/1271/CH2/EX2.45/45.txt
new file mode 100755
index 000000000..2ee509548
--- /dev/null
+++ b/1271/CH2/EX2.45/45.txt
@@ -0,0 +1 @@
+ Numerical aperture of objective = 0.832803
\ No newline at end of file
diff --git a/1271/CH2/EX2.45/example2_45.sce b/1271/CH2/EX2.45/example2_45.sce
new file mode 100755
index 000000000..c27fb684b
--- /dev/null
+++ b/1271/CH2/EX2.45/example2_45.sce
@@ -0,0 +1,9 @@
+clc 
+// Given that
+lambda = 5.461e-7 // wavelength of light in meter
+d = 4e-7 // separation between objects in meter
+// Sample Problem 45 on page no. 2.55
+printf("\n # PROBLEM 45 # \n")
+NA = (1.22 * lambda) / (2 * d) // calculation for numerical aperture of objective 
+printf("\n Standard formula used \n NA = (1.22 * lambda) / (2 * d). \n")
+printf("\n Numerical aperture of objective = %f",NA)
diff --git a/1271/CH2/EX2.5/5.txt b/1271/CH2/EX2.5/5.txt
new file mode 100755
index 000000000..129c64a7a
--- /dev/null
+++ b/1271/CH2/EX2.5/5.txt
@@ -0,0 +1 @@
+Distance of screen from opening = 0.500000 meter 
\ No newline at end of file
diff --git a/1271/CH2/EX2.5/example2_5.sce b/1271/CH2/EX2.5/example2_5.sce
new file mode 100755
index 000000000..40b432468
--- /dev/null
+++ b/1271/CH2/EX2.5/example2_5.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+lambda = 5e-7 // wavelength of light in meter
+d = 1e-3 // diameter of the first ring of zone plate in meter
+// Sample Problem 5 on page no. 2.39
+printf("\n # PROBLEM 5 # \n")
+n = 1 // no. of half period zone
+D = (d^2) / (4 * lambda * n) // calculation for distance of screen from opening
+printf("\n Standard formula used \n D = (d^2) / (4 * lambda * n). \n")
+printf("\n Distance of screen from opening = %f meter ",D)
diff --git a/1271/CH2/EX2.6/6.txt b/1271/CH2/EX2.6/6.txt
new file mode 100755
index 000000000..e6b57b9db
--- /dev/null
+++ b/1271/CH2/EX2.6/6.txt
@@ -0,0 +1,2 @@
+

+ Radius of first ,second and third half period zone = 7.676588e-04,1.329624e-03 and 1.716537e-03 meter. 

diff --git a/1271/CH2/EX2.6/example2_6.sce b/1271/CH2/EX2.6/example2_6.sce
new file mode 100755
index 000000000..c3e34df74
--- /dev/null
+++ b/1271/CH2/EX2.6/example2_6.sce
@@ -0,0 +1,14 @@
+clc 
+// Given that
+lambda = 5.893e-7 // wavelength of light in meter
+f = 1 // focal-length of convex lens in meter
+n1 = 1 // no. of first half period zone
+n2 = 3 // no. of second half period zone
+n3 = 5 // no. of third half period zone
+// Sample Problem 6 on page no. 2.40
+printf("\n # PROBLEM 6 # \n")
+R1 = sqrt(n1 * lambda * f) // calculation for Radius of first half period zone
+R2 = sqrt(n2 * lambda * f) // calculation for Radius of second half period zone
+R3 = sqrt(n3 * lambda * f) // calculation for Radius of third half period zone
+printf("Standard formula used \n R = sqrt(f*n*lambda)\n")
+printf("\n Radius of first ,second and third half period zone = %e,%e and %e meter. ",R1,R2,R3)
diff --git a/1271/CH2/EX2.7/7.txt b/1271/CH2/EX2.7/7.txt
new file mode 100755
index 000000000..1781a25c6
--- /dev/null
+++ b/1271/CH2/EX2.7/7.txt
@@ -0,0 +1,2 @@
+

+ Radius of 10th half period zone = 0.001000 meter. 

diff --git a/1271/CH2/EX2.7/example2_7.sce b/1271/CH2/EX2.7/example2_7.sce
new file mode 100755
index 000000000..698a85d50
--- /dev/null
+++ b/1271/CH2/EX2.7/example2_7.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+lambda = 5e-7 // wavelength of light in meter
+f = 0.2 // focal length of convex lens in meter
+n = 10 // no. of half period zone
+// Sample Problem 7 on page no. 2.40
+printf("\n # PROBLEM 7 # \n")
+Rn = sqrt(n * lambda * f) // calculation for radius of 10th half period zone
+printf("\n Standard formula used \n Rn = sqrt(n * lambda * f).\n")
+printf("\n Radius of 10th half period zone = %f mm. ",Rn*1000)
diff --git a/1271/CH2/EX2.8/8.txt b/1271/CH2/EX2.8/8.txt
new file mode 100755
index 000000000..809151209
--- /dev/null
+++ b/1271/CH2/EX2.8/8.txt
@@ -0,0 +1,3 @@
+ Focal length = 6.666667e-01 meter. 

+ Power = 1.500000 D. 

+ Diameter of first zone = 1.253262e-03 meter. 

diff --git a/1271/CH2/EX2.8/example2_8.sce b/1271/CH2/EX2.8/example2_8.sce
new file mode 100755
index 000000000..9af0ace91
--- /dev/null
+++ b/1271/CH2/EX2.8/example2_8.sce
@@ -0,0 +1,14 @@
+clc 
+// Given that
+lambda = 5.89e-7 // wavelength of light in meter
+d1 = 1 // distance of wavefront recieved on the screen from the opening in first side in meter
+d2 = 2 // distance of wavefront recieved on the screen from the opening in other side in meter
+// Sample Problem 8 on page no. 2.40
+printf("\n # PROBLEM 8 # \n")
+f = (d1 * d2) / (d1 + d2)
+p = 1 / f // beacause zone plate act as a convex lens
+n = 1 // for first zone
+Rn = sqrt(n * lambda * f) // calculation for radius of first zone
+Dn = 2 * Rn // calculation for diameter of first zone
+printf("\n Standard formula used \n ")
+printf("\n Focal length = %f meter. \n Power = %f D. \n Diameter of first zone = %f mm. ",f,p,Dn*1000)
diff --git a/1271/CH2/EX2.9/9.txt b/1271/CH2/EX2.9/9.txt
new file mode 100755
index 000000000..6f6e233d5
--- /dev/null
+++ b/1271/CH2/EX2.9/9.txt
@@ -0,0 +1 @@
+ Focal length in second case = 1.200000 meter
\ No newline at end of file
diff --git a/1271/CH2/EX2.9/example2_9.sce b/1271/CH2/EX2.9/example2_9.sce
new file mode 100755
index 000000000..a7d137967
--- /dev/null
+++ b/1271/CH2/EX2.9/example2_9.sce
@@ -0,0 +1,10 @@
+clc 
+// Given that
+lambda1 = 6e-7 // wavelength of first light in meter
+lambda2 = 5e-7 // wavelength of second light in meter
+f1 = 1 // focal length in first case in meter 
+// Sample Problem 9 on page no. 2.41
+printf("\n # PROBLEM 9 # \n")
+f2 = (lambda1 * f1) / lambda2 // calculation for focal length in second case
+printf("\n Standard formula used \n f2 = (lambda1 * f1) / lambda2")
+printf("\n Focal length in second case = %f meter",f2)