1 files changed, 22 insertions, 0 deletions
diff --git a/1938/CH3/EX3.8/3_8.sce b/1938/CH3/EX3.8/3_8.sce
new file mode 100755
index 000000000..3b7f24cd0
--- /dev/null
+++ b/1938/CH3/EX3.8/3_8.sce
@@ -0,0 +1,22 @@
+clc,clear
+printf('Example 3.8\n\n')
+
+V=500
+Io=5 //no load current
+R_a=0.5,R_sh=250//resistance of armature and field circuits
+I=100 //current at unknown efficiency
+
+P_in_NL=V*Io  //no load input
+I_sh=V/R_sh
+
+Iao=Io-I_sh
+arm_cu_loss_no_load=R_a*Iao^2  //No load armature copper loss
+constant_losses= P_in_NL- arm_cu_loss_no_load
+
+I_a=I-I_sh
+arm_cu_loss= R_a*I_a^2  //New armature copper loss
+
+Total_loss=arm_cu_loss + constant_losses
+P_in=V*I
+efficiency=(P_in-Total_loss)*100/P_in //required efficiency
+printf('Efficiency is %.3f percent when motor takes %.0f A current',efficiency,I)