Q. A primary cell has an $e.m.f.$ of 1.5 volt, when short-circuited it gives a current of 3 ampere. The internal resistance of the cell is
A) $4.5\ ohm$
B) $2\ ohm$
C) $0.5\ ohm$
D) $1/4.5\ ohm$
Explanation
(c) Short circuit current $i_{SC} = \frac{E}{r} \Rightarrow 3 = \frac{1.5}{r} \Rightarrow r = 0.5\Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.