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+//Chapter 5:DC Motor Drives
+//Example 2
+clc;
+
+//Variable Initialization
+
+V1=220      //rated voltage in V
+Ia1=100     //rated current in A
+N1=1000     //rated speed in rpm clockwise
+Ra=0.05     //armature resistance in ohms
+Rs=0.05     //field resistance in ohms
+
+//Solution
+//Turns is reduced to 80% then flux is also reduced by the same value and hence current is also reduced
+T1=Ia1**2      //flux is directly proportional to current Ia
+T2=0.8*1**2  //flux is directly proportional to current Ia
+Ia2=-Ia1/sqrt(0.8)   //since T1=T2 and the direction is opposite
+
+E1=V1-Ia1*(Ra+Rs)
+
+Rs=.8*Rs       //Rs=80% of the field resistance 0.05ohm since the flux is reduced to 80%
+E2=-(V1+Ia2*(Ra+Rs))   
+
+N2=(E2/E1)*(Ia1/Ia2)*(N1/0.8)   //since E=Kn*flux*N
+
+//Result
+mprintf("\nMotor speed is:N2=%.1f rpm",N2)