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diff --git a/3760/CH4/EX4.70/Ex4_70.sce b/3760/CH4/EX4.70/Ex4_70.sce
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+clc;
+v=240; // rated voltage of motor and supply voltage
+i=5.2; // line current
+p=10000; // rated power of motor
+no=1200; // no load speed
+ra=0.25; // armature resistance
+rf=160; // field resistance
+ifl=v/rf; // constant field current
+iao=i-ifl; // no load armature current
+wo=v*iao-iao^2*ra; // no load rotational losses
+//  by using equation of electromagnetic power solving quadratic equation in armature current whose terms are
+t1=ra; 
+t2=-v; 
+t3=p+wo;
+P=[ t1 t2 t3 ];
+ia=roots(P);
+pi=(v-ia(2)*ra)*ia(2)+ia(2)^2*ra+ifl*v; // motor input
+nm=(p/pi)*100;
+printf('Motor efficiency at rated load is %f percent',nm);