Problem 14: A current of 5A through a battery is maintained for 30 seconds and in this time 600J of chemical energy is transferred into electrical energy. What is the e.m.f of battery? How much power is available for heating and other uses?
Solution:
Step: 1 Overview
See the overview of problem 3.
Step: 2 Calculation
Given:I=5ARequired:
W=600J
time(t)=30s
P=?Solution:
V=?
We know that,
P=W/t
P=(600J)/(30s)
P=20W
Also we know that,
P=VI
V=P/I
V=(20W)/(5A) V=4V
P=20W, and V=4V (Ans)
