diff options
Diffstat (limited to '3760/CH8')
| -rw-r--r-- | 3760/CH8/EX8.1/ExA_1.sce | 14 | ||||
| -rw-r--r-- | 3760/CH8/EX8.10/ExA_10.sce | 7 | ||||
| -rw-r--r-- | 3760/CH8/EX8.12/ExA_12.sce | 22 | ||||
| -rw-r--r-- | 3760/CH8/EX8.13/ExA_13.sce | 14 | ||||
| -rw-r--r-- | 3760/CH8/EX8.2/ExA_2.sce | 13 | ||||
| -rw-r--r-- | 3760/CH8/EX8.3/ExA_3.sce | 35 | ||||
| -rw-r--r-- | 3760/CH8/EX8.4/ExA_4.sce | 24 | ||||
| -rw-r--r-- | 3760/CH8/EX8.5/ExA_5.sce | 22 | ||||
| -rw-r--r-- | 3760/CH8/EX8.6/ExA_6.sce | 28 | ||||
| -rw-r--r-- | 3760/CH8/EX8.7/ExA_7.sce | 24 | ||||
| -rw-r--r-- | 3760/CH8/EX8.8/ExA_8.sce | 19 | ||||
| -rw-r--r-- | 3760/CH8/EX8.9/ExA_9.sce | 21 |
12 files changed, 243 insertions, 0 deletions
diff --git a/3760/CH8/EX8.1/ExA_1.sce b/3760/CH8/EX8.1/ExA_1.sce new file mode 100644 index 000000000..a478018e7 --- /dev/null +++ b/3760/CH8/EX8.1/ExA_1.sce @@ -0,0 +1,14 @@ +clc;
+// answer is given wrong in the book
+d=0.2; // mean diameter of mild steel ring
+ac=50*10^-4; // cross sectional area of core
+uo=4*%pi*10^-7; // free space permeability
+ur=800; // relative permeability
+f=1*10^-3; // required flux
+N=200; // Number of turns
+l=%pi*d // length of core
+R=l/(uo*ur*ac); // reluctance of ring
+printf('reluctance offered by ring is %f AT/Wb\n',R);
+mmf=f*R; // mmf produced in ring
+i=mmf/N;
+printf('current required to produce the desired flux is %f A',i);
diff --git a/3760/CH8/EX8.10/ExA_10.sce b/3760/CH8/EX8.10/ExA_10.sce new file mode 100644 index 000000000..6899006fd --- /dev/null +++ b/3760/CH8/EX8.10/ExA_10.sce @@ -0,0 +1,7 @@ +clc;
+l=0.5; // length of conductor lying along Y-axis
+B=1.2; // Flux density along the X-axis
+v=2; // velocity of conductor
+//e=Blv; for maximum induced emf all the three quantities should be perpendicular to each other
+e=B*l*v;
+printf('Maximum induced EMF in conductor is %f V',e);
diff --git a/3760/CH8/EX8.12/ExA_12.sce b/3760/CH8/EX8.12/ExA_12.sce new file mode 100644 index 000000000..2c6304242 --- /dev/null +++ b/3760/CH8/EX8.12/ExA_12.sce @@ -0,0 +1,22 @@ +clc;
+disp('case a');
+// as per the data taken from Ex 1_3
+rlg=24.948*10^5; // air gap reluctance for example 1_3(a)
+rlc=12.474*10^5; // iron core reluctance for example 1_3(a)
+rl=rlg+rlc; // net reluctance
+N=500; // Number of turns
+L=(N^2/rl)*1000;
+printf('Inductance for case a is %f mH\n',L);
+disp('case b');
+// as per the data taken from Ex 1_3 part(c)
+B=1.254; // calculated flux density
+H=3200; // magnetic field intensity obtained from magnetisation curve corresponding to the flux density calculated
+uo=4*%pi*10^-7; // free space permeability
+ur=B/(H*uo); // relative permeability of iron core
+d=2.85*10^-2; // diameter of cross section
+A=(%pi*d^2)/4; // area of core
+l=0.5; // core length
+rlc=l/(ur*uo*A); // reluctance of iron core for part C
+rt=rlg+rlc; // net reluctance
+L=(N^2/rt)*1000;
+printf('Inductance for case b is %f mH\n',L);
diff --git a/3760/CH8/EX8.13/ExA_13.sce b/3760/CH8/EX8.13/ExA_13.sce new file mode 100644 index 000000000..0c47fce1a --- /dev/null +++ b/3760/CH8/EX8.13/ExA_13.sce @@ -0,0 +1,14 @@ +clc;
+// data taken from Ex A.7, fig A.16
+N1=200; // number of turns in coil 1
+f1=53.97*10^-3; // flux in outer limb containing coil 1
+m1=5000; // mmf for coil 1
+I1=m1/N1; // current in coil 1
+N2=100; // number of turns in coil 2
+f2=43.97*10^-3; // flux in outer limb containing coil 2
+m2=1102; // mmf for coil 2
+I2=m2/N2; // current in coil 2
+L1=(N1*f1)/I1;
+printf('Inductance for coil 1 is %f H\n',L1);
+L2=(N2*f2)/I2;
+printf('Inductance for coil 2 is %f H\n',L2);
diff --git a/3760/CH8/EX8.2/ExA_2.sce b/3760/CH8/EX8.2/ExA_2.sce new file mode 100644 index 000000000..7055ff815 --- /dev/null +++ b/3760/CH8/EX8.2/ExA_2.sce @@ -0,0 +1,13 @@ +clc;
+ur=10000; // relative permeability of iron
+lc=0.5; // core length
+lg=4*10^-3; // air gap length
+N=600; // number of turns
+B=1.2; // desired flux density
+uo=4*%pi*10^-7; // free space permeability
+Ac=25*10^-4; // core area
+mfc=(B*lc)/(uo*ur); // mmf for core
+mfg=(B*lg)/uo; // mmf for air gap
+mft=mfc+mfg; // net mmf
+i=mft/N;
+printf('exciting current required to establish the desired flux is %f A',i);
diff --git a/3760/CH8/EX8.3/ExA_3.sce b/3760/CH8/EX8.3/ExA_3.sce new file mode 100644 index 000000000..7c06456b2 --- /dev/null +++ b/3760/CH8/EX8.3/ExA_3.sce @@ -0,0 +1,35 @@ +clc;
+lc=0.5; // core length in metre
+dc=2.85*10^-2; // diameter of cross section of core
+lg=2*10^-3; // length of air gap
+N=500; // Number oof turns of coil
+f=0.8*10^-3; // air gap flux
+uo=4*%pi*10^-7; // permeability of free space
+HATM=[1500 2210 2720 3500 4100];
+BT=[0.9 1.1 1.2 1.275 1.3];
+plot(HATM,BT);
+xlabel('magnetic field intensity');
+ylabel('flux density');
+disp('case a');
+ur=500; // relative permeability
+Ac=(%pi/4)*dc^2; // Area of core
+Rlg=lg/(uo*Ac); // reluctance of air gap
+Rlc=lc/(uo*ur*Ac); // reluctance of iron core
+Rt=Rlg+Rlc; // Total reluctance
+I=(f*Rt)/N; // Exciting current
+printf('Exciting current in coil is %f A\n',I);
+disp('case b');
+Ag=(%pi/4)*(dc+2*lg)^2; // air gap area
+Rlg=lg/(uo*Ag); // reluctance of air gap
+I=(f*(Rlc+Rlg))/N; // Exciting current
+printf('Exciting current after accounting for flux fringing is %f A\n',I);
+disp('case c');
+Bg=f/Ac; // Air gap flux density
+Atg=(Bg*lg)/uo; // air gap mmf
+// from the plot we can get the values of core flux density and magnetic field intensity
+Bc=1.245; // core flux density in Tesla
+H=3200; // magnetic field intensity in Ats/m
+Atc=H*lc; // core mmf
+mt=Atg+Atc; // total mmf
+I=mt/N; // Exciting current
+printf('Exciting current for third case is %f A',I);
diff --git a/3760/CH8/EX8.4/ExA_4.sce b/3760/CH8/EX8.4/ExA_4.sce new file mode 100644 index 000000000..3b10615de --- /dev/null +++ b/3760/CH8/EX8.4/ExA_4.sce @@ -0,0 +1,24 @@ +clc;
+N=1000; // Number of turns
+f=1*10^-3; // flux in central limb
+Ac=8*10^-4; // Area of central limb
+Ao=4*10^-4; // Area of outer limb
+lg=2*10^-3; // length of air gap
+lc=0.15; // length of central limb in metre
+lo=0.25; // length of outer limb in metre
+uo=4*%pi*10^-7; // permeability of free space
+disp('case a');
+// for ur=infinity, reluctance offered by cast steel is zero
+Rl1=lg/(uo*Ao); // reluctance offered by outer limb
+Rl2=lg/(uo*Ac); // reluctance offered by central limb
+// Assuming magnetic circuit as a close circuit, applying KVl in one of loop gives
+I=(f*(Rl2+(Rl1/2)))/N;
+printf('Coil current for first case is %f A\n',I);
+disp('case b');
+ur=6000; // relative permability
+Rlc1=(lc+lo)/(uo*ur*Ao); // reluctance of outer steel core (including the top)
+Rlc2=(lc)/(uo*ur*Ac); // reluctance offered by central steel core
+r=(Rlc1+Rl1)/2; // resultant of outer reluctance
+// By kVL we get
+I=(f*(Rlc2+Rl2+r))/N;
+printf('Coil current for second case is %f A\n',I);
diff --git a/3760/CH8/EX8.5/ExA_5.sce b/3760/CH8/EX8.5/ExA_5.sce new file mode 100644 index 000000000..4db15d1ed --- /dev/null +++ b/3760/CH8/EX8.5/ExA_5.sce @@ -0,0 +1,22 @@ +clc;
+N=500; // number of turns in central limb
+ac=600*10^-6; // cross sectional area of central limb
+ao=375*10^-6; // cross sectional area of outer limb
+f=0.9*10^-3; // required flux in Weber
+lg=0.8*10^-3; // length of air gap
+lc=180*10^-3; // length of central limb
+lo=400*10^-3; // length of outer limb
+uo=4*%pi*10^-7; // free space permeability
+Bg=f/ac; // air gap flux density
+Hg=Bg/uo; // magnetic field intensity in air gap
+mg=Hg*lg; // mmf required for air gap
+// from fig A.7,for B=1.5T, H for cast steel is 3000Ats/m
+H=3000; // magnetic field intensity for cast steel
+mc=H*lc; // mmf in central limb
+Bo=f/(2*ao); // flux density in each outer limb
+// for B=1.2, H=1400
+H=1400; // magnetic field intensity for cast steel for given flux density
+mo=H*lo; // mmf for outer limb
+// By KVL
+I=(mg+mo+mc)/N;
+printf('The exciting current required to establish the desired flux is %f A',I);
diff --git a/3760/CH8/EX8.6/ExA_6.sce b/3760/CH8/EX8.6/ExA_6.sce new file mode 100644 index 000000000..14fb9ba3e --- /dev/null +++ b/3760/CH8/EX8.6/ExA_6.sce @@ -0,0 +1,28 @@ +clc;
+N=400; // number of turns in coil
+ac=20*10^-4; // area of cemntral limb
+ao=15*10^-4; // area of outer iimb
+lg=1*10^-3; // length of air gap
+lc=40*10^-2; // length of central limb
+lo=60*10^-2; // length of each outer limb
+f=0.9*10^-3; // required flux
+uo=4*%pi*10^-7; // free space permeability
+Bg=f/ao; // air gap flux density
+mg=(Bg*lg)/uo; // mmf or air gap
+// for B=0.6,H=575 AT/m from fig A.7
+H=575; // magnetic flux intensity for given flux density
+mo=H*lo; // mmf of outer limb which contain air gap
+mt=mo+mg; // combined mmf of air gap and outer limb
+// this mmf acts across the other outer limb
+haeb=mt/lo; // magnetic field intensity in outer limb which does not contain air gap
+// for H=1370.77, B=1.19 T from fig A.7
+Bo=1.19; // flux density for given magnetic field intensity
+faeb=Bo*ao; // flux in outer limb
+fnet=f+faeb; // net flux through central limb
+Bc=fnet/ac; // flux density in central limb
+// from fig A.7
+H=1900; // magnetic field intensity for given flux density
+mc=H*lc; // mmf in central limb
+// by KVL in one of the loop
+I=(mc+mt)/N;
+printf('Exciting current required to establish the given flux is %f A',I)
diff --git a/3760/CH8/EX8.7/ExA_7.sce b/3760/CH8/EX8.7/ExA_7.sce new file mode 100644 index 000000000..78976b45f --- /dev/null +++ b/3760/CH8/EX8.7/ExA_7.sce @@ -0,0 +1,24 @@ +clc;
+a=30*10^-4; // cross sectional area of ferromagnetic core
+uo=4*%pi*10^-7; // free space permeability
+ur=4000; // relative permeability for core
+f=10*10^-3; // flux in central limb
+n1=200; // number of turns in coil 1
+m1=5000; // mmf for coil 1
+n2=100; // number of turns in coil 2
+lc=0.3; // length of central limb
+lo=0.6; // length of outer limb
+lg=1*10^-3; // length of air gap
+rc=lc/(uo*ur*a); // reluctance for central limb
+ro=lo/(uo*ur*a); // reluctance for outer limb
+rg=lg/(uo*a); // reluctance for air gap
+mc=f*(rc+rg); // mmf in central limb
+// by KML, flux in outer limb containing coil 1 is
+f1=(m1-mc)/ro;
+// By flux law at node a in fig A.17, flux in outer limb contaning coil 2 is
+f2=f1-f;
+// by mmf law , mmf in coil 2 is
+m2=mc-f2*ro;
+I2=m2/n2; // current in coil 2, upper polarity is assumed positive
+printf('Current in coil 2 is %f A',I2);
+disp('As the mmf of coil 2 is positive , assumed polarity is correct. Therefore terminal A is positive because current enters through it and terminal B is negative ');
diff --git a/3760/CH8/EX8.8/ExA_8.sce b/3760/CH8/EX8.8/ExA_8.sce new file mode 100644 index 000000000..3820eeb03 --- /dev/null +++ b/3760/CH8/EX8.8/ExA_8.sce @@ -0,0 +1,19 @@ +clc;
+l=0.8; // length of conductor
+B=1.2; // flux density of uniform magnetic field
+v=30; // speed of conductor
+disp('case a');
+// conductor motion is normal to field flux
+theta=90; // angle between direction of motion and field flux
+e=B*l*v*sin(theta*(%pi/180));
+printf('EMF induced is %f V\n',e);
+disp('case b');
+// conductor motion is at an angle of 30 degrees from direction of field
+theta=30; // angle between direction of motion and field flux
+e=B*l*v*sin(theta*(%pi/180));
+printf('EMF induced is %f V\n',e);
+disp('case c');
+// conductor motion is parllel to field flux
+theta=0; // angle between direction of motion and field flux
+e=B*l*v*sin(theta*(%pi/180));
+printf('EMF induced is %f V\n',e);
diff --git a/3760/CH8/EX8.9/ExA_9.sce b/3760/CH8/EX8.9/ExA_9.sce new file mode 100644 index 000000000..74e3923a3 --- /dev/null +++ b/3760/CH8/EX8.9/ExA_9.sce @@ -0,0 +1,21 @@ +clc;
+// After deriving the expression
+a=0.1; // side of square coil
+N=100; // number of turns
+n=1000; // speed of rotation on rpm
+B=1; // flux density of a uniform magnetic field
+disp('case a');
+theta=90; // angle of coil with the field
+w=(2*%pi*n)/60; // angular speed of coil in rad/s
+e=N*B*a^2*w*cos(theta*(%pi/180));
+printf('Emf induced in coil is %f V\n',e);
+disp('case b');
+theta=30; // angle of coil with the field
+w=(2*%pi*n)/60; // angular speed of coil in rad/s
+e=N*B*a^2*w*cos(theta*(%pi/180));
+printf('Emf induced in coil is %f V\n',e);
+disp('case c');
+theta=0; // angle of coil with the field
+w=(2*%pi*n)/60; // angular speed of coil in rad/s
+e=N*B*a^2*w*cos(theta*(%pi/180));
+printf('Emf induced in coil is %f V\n',e);
|