Current Electricity Charging Discharging Of Capacitors Question 209

Question: A potentiometer is used for the comparison of e.m.f. of two cells $ E _{1} $ and $ E _{2} $ . For cell $ E _{1} $ the no deflection point is obtained at 20 $ cm $ and for $ E _{2} $ the no deflection point is obtained at 30 $ cm $ . The ratio of their e.m.f.’s will be

[MP PET 1984]

Options:

A) 2/3

B) 1/2

C) 1

D) 2

Show Answer

Answer:

Correct Answer: A

Solution:

Ratio will be equal to the ratio of no deflection lengths i.e. $ \frac{E _{1}}{E _{2}}=\frac{l _{1}}{l _{2}}=\frac{2}{3} $