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//CHAPTER 8- DIRECT CURRENT MACHINES
//Example 16
disp("CHAPTER 8");
disp("EXAMPLE 16");
//VARIABLE INITIALIZATION
v_t=250; //in Volts
P=4; //number of poles
Z=500; //number of conductors
r_a=0.25; //in Ohms
r_f=125; //in Ohms
phi=0.02; //in Wb
I_l=14; //in Amperes
A=2;
rot_loss=300; //rotational loss in Watts
//SOLUTION
//solution (i)
I_f=v_t/r_f;
I_a=I_l-I_f;
E_a=v_t-(I_a*r_a);
N=(E_a*A*60)/(phi*Z*P);
N=round(N); //to round off the value of N
disp(sprintf("(i) The speed is %d rpm",N));
p_e=E_a*I_a;
w=(2*%pi*N)/60;
T1=p_e/w;
disp(sprintf("The internal torque developed is %f N-m",T1));
//solution (ii)
p_o=p_e-rot_loss;
disp(sprintf("(ii)The shaft power is %f W",p_o));
T2=p_o/w;
disp(sprintf("The shaft torque is %f N-m",T2));
p_i=v_t*I_l;
eff=(p_o/p_i)*100;
disp(sprintf("The efficiency is %f %%",eff));
//END
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