1 files changed, 15 insertions, 0 deletions
diff --git a/3760/CH4/EX4.49/Ex4_49.sce b/3760/CH4/EX4.49/Ex4_49.sce
new file mode 100644
index 000000000..2dc47cbce
--- /dev/null
+++ b/3760/CH4/EX4.49/Ex4_49.sce
@@ -0,0 +1,15 @@
+clc;
+v=250; // rated voltage of dc shunt motor
+ra=0.5; // armature resistance
+rf=250; // field resistance
+n1=600; // speed of motor
+i=21; // current drawn by motor when n=600 rpm
+re=250; // additional resistance in field circuit
+if1=v/rf; // field current
+ia=i-if1; // armature current
+Ea1=v-ia*ra; // counter EMF at n=600 rpm
+if2=v/(rf+re); // field current after addition of external resistance 
+ia2=ia*(if1/if2); // armature current after addition of external resistance 
+Ea2=v-ia2*ra; // counter EMF at new speed
+n2=(n1*Ea2*if1)/(Ea1*if2);
+printf('New speed of motor is %f rpm',n2);