0

Guest

Courses New

Why should the EMF of the driver cell be greater than that whose EMF is to be determined ?

Why should the EMF of the driver cell be greater than that whose EMF is to be determined ?

Grade:12

3 Answers

jyoti dogra
29 Points
12 years ago
EMF of the driver cell should be higher than the e.m.f.s of each of the two cells being compared to obtain the balance point.Otherwise, null point or balanced point cannot be obtained.
Yashi Gupta
34 Points
7 years ago
Emf of driver cell should be greater because as the circuit starts the potential is dropped across the resistor and more emf is needed to drive current in the circuit
Sheetal
15 Points
7 years ago
Because the max. potential difference across the resistance wire of potentiometer is the emf of driver cell. Thus emfs to be measured will be balanced in between the extreme points of the resistance wire of potentiometer only if their emf is less than the emf of driver cell. Eg. If we try to measure the length of a line segment, for accuracy, the ruler/scale we use must be longer than the length of line segment. Same way, resistance wire of potentiometer acts a scale to measure potential drop. Thus potential drop across that wire and hence emf of driver cell must be more than the emf to be measured.

Think You Can Provide A Better Answer ?

Other Related Questions on Electric Current

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More