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diff --git a/3760/CH4/EX4.75/Ex4_75.sce b/3760/CH4/EX4.75/Ex4_75.sce
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+clc;
+v=400; // rated voltage of dc shunt motor
+p=20000; // rated power of motor
+i=2.5; // no load current 
+ra=0.5; // armature resistance
+rf=800; // field current
+vb=2; // voltage drop in brush
+ifl=v/rf; // constant shunt field current
+iao=i-ifl; // no load armature current
+wo=v*iao-iao^2*ra; // no load rotational losses
+tl=wo+v*ifl; // total losses
+//  by using equation of power input= output power + losses, solving quadratic equation in armature current whose terms are
+t1=ra;
+t2=vb-v; 
+t3=p+tl-v*(v/rf);
+P=[ t1 t2 t3];
+ia=roots(P);
+lo=ia(2)^2*ra; // armature ohmic losses
+lb=ia(2)*vb; // brush drop loss
+tl=tl+lo+lb; // total losses at rated load
+pi=p+tl; // input power 
+nm=(p/pi)*100;
+printf('Full load efficiency is %f percent',nm);