updated the code

1 files changed, 12 insertions, 25 deletions

diff --git a/1445/CH8/EX8.17/Ex8_17.sce b/1445/CH8/EX8.17/Ex8_17.sce
index 6e4141500..0ca2818cc 100644
--- a/1445/CH8/EX8.17/Ex8_17.sce
+++ b/1445/CH8/EX8.17/Ex8_17.sce
@@ -1,58 +1,45 @@
 //CHAPTER 8- DIRECT CURRENT MACHINES
 //Example 17
 
+clc;
 disp("CHAPTER 8");
 disp("EXAMPLE 17");
 
-//200 V DC shunt motor of 1000 rpm
 //VARIABLE INITIALIZATION
 v_t=200;                   //in Volts
-I_l=22;                    //line current in Amperes
+I_l=22;                    //in Amperes
 N1=1000;                   //in rpm
-r_a=0.1;                   //armature resistancein Ohms
-r_f=100;                   //field resistance in Ohms
-N2=800;                    //new speed in rpm
+r_a=0.1;                   //in Ohms
+r_f=100;                   //in Ohms
+N2=800;                    //in rpm
 
 //SOLUTION
 
 //solution (i)
-//load torque is independent of speed, the torque is constant at both speeds
-//T dir prop phi1.Ia1 dir prop phi2.Ia2
-//Therefore we get
-//phi1.Ia1=phi2.Ia2 (since phi1=phi2)
-// or Ia1=Ia2
-I_f=v_t/r_f;                // field current
-I_a1=I_l-I_f;               // armature current
-E_a1=v_t-(I_a1*r_a);        // counter emf
+I_f=v_t/r_f;
+I_a1=I_l-I_f;
+E_a1=v_t-(I_a1*r_a);
 //on rearranging the equation E_a2:E_a1=N2:N1, where E_a2=v_t-I_a1*(r_a+r_s) and E_a1=v_t-(I_a1*r_a), we get,
 r_s1=((v_t - ((N2*E_a1)/N1))/I_a1)-r_a;
-disp(sprintf("(i) When the load torque is independent of speed, the additional resistance is %.2f Ω",r_s1));
+disp(sprintf("(i) When the load torque is independent of speed, the additional resistance is %f Ω",r_s1));
 
 //solution (ii)
-//Load torque Tl is proportional to N
-//But electromagnetic torque Te=k.phi.Ia
-//therefore, 
-//k.phi1.Ia1 dir prop N1
-//k.phi2.Ia2 dir prop n2
-//hence we get (as phi1=phi2)
 I_a2=(N2/N1)*I_a1;
 //on rearranging the equation E_a2:E_a1=N2:N1, where E_a2=v_t-I_a2*(r_a+r_s) and E_a1=v_t-(I_a1*r_a), we get,
 r_s2=((v_t - ((N2*E_a1)/N1))/I_a2)-r_a;
-disp(sprintf("(ii)When the load torque is proportional to speed, the additional resistance is %.1f Ω",r_s2));
+disp(sprintf("(ii)When the load torque is proportional to speed, the additional resistance is %f Ω",r_s2));
 
 //solution (iii)
-//The load Torque Tl dir prop N^2 dir prop phi.Ia
 I_a2=(N2^2/N1^2)*I_a1; 
 //on rearranging the equation E_a2:E_a1=N2:N1, where E_a2=v_t-I_a2*(r_a+r_s) and E_a1=v_t-(I_a1*r_a), we get,
 r_s3=((v_t - ((N2*E_a1)/N1))/I_a2)-r_a;
-disp(sprintf("(iii)When the load torque varies as the square of speed, the additional resistance is %.2f Ω",r_s3));
+disp(sprintf("(iii)When the load torque varies as the square of speed, the additional resistance is %f Ω",r_s3));
 
 //solution (iv)
-//The load Torque Tl dir prop N^3 dir prop phi.Ia
 I_a2=(N2^3/N1^3)*I_a1;
 //on rearranging the equation E_a2:E_a1=N2:N1, where E_a2=v_t-I_a2*(r_a+r_s) and E_a1=v_t-(I_a1*r_a), we get,
 r_s4=((v_t - ((N2*E_a1)/N1))/I_a2)-r_a;
-disp(sprintf("(iv)When the load torque varies as the cube of speed, the additional resistance is %.2f Ω",r_s4));
+disp(sprintf("(iv)When the load torque varies as the cube of speed, the additional resistance is %f Ω",r_s4));
 
 //END