wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

When a resistance of 2 ohms is connected across the terminals of a cell, the current is 0.5 A. When the resistance is increased to 5 ohms, the current becomes 0.25 A. The e.m.f. of the cell is :-

A
1.0 V
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
1.5 V
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
2.0 V
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
2.5 V
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 1.5 V
Given, Resistance=2Ω,current=0.5A When the resistance is increased to 5Ω the current is 0.25A

The emf of the cell isE=5×(r+2)=12×(r+2)....1

When resistance is increased by 5Ω the current is 0.25A Then, E=0.25×(r+5)=(14)(r+5)......2

From equation 1 and 2 we get,

r=1Ω now put this value in equation 1 then we get E=32=1.5v

flag
Suggest Corrections
thumbs-up
1
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Simple Circuit
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon