From 7f60ea012dd2524dae921a2a35adbf7ef21f2bb6 Mon Sep 17 00:00:00 2001
From: prashantsinalkar
Date: Tue, 10 Oct 2017 12:27:19 +0530
Subject: initial commit / add all books

---
 3760/CH4/EX4.74/Ex4_74.sce | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 3760/CH4/EX4.74/Ex4_74.sce

(limited to '3760/CH4/EX4.74/Ex4_74.sce')

diff --git a/3760/CH4/EX4.74/Ex4_74.sce b/3760/CH4/EX4.74/Ex4_74.sce
new file mode 100644
index 000000000..aca6ba82f
--- /dev/null
+++ b/3760/CH4/EX4.74/Ex4_74.sce
@@ -0,0 +1,22 @@
+clc;
+v=400; // rated voltage of dc shunt motor
+io=5; // current at no load
+ra=0.5; // armature resistance
+rf=200; // field resistance
+i=50; // current at full load
+ifl=v/rf; // constant shunt field current
+iao=io-ifl; // no load armature current
+wo=v*iao-iao^2*ra; // no load rotational losses
+ia=i-ifl; // full load armature current
+la=ia^2*ra; // full load armature circuit losses
+lf=v*ifl; // constant shunt feld losses
+tl=la+lf+wo; // total field losses
+pi=i*v; // motor input at full load
+nm=(1-(tl/pi))*100;
+printf('Output power is %f KW\n',(pi-tl)/1000);
+printf('Efficiency on full load is %f percent\n',nm);
+Ea1=v-iao*ra; // no load counter EMF
+Ea2=v-ia*ra; // full load counter EMF
+pr=((Ea1-Ea2)/Ea1)*100; // Ea is directly proportioal to speed so percentage change in Ea is same as percentage in speed;
+
+printf('Percentage change in speed from no load to full load is %f percent',pr);  
-- 
cgit