Q. A battery has e.m.f.$\ 4\ V$ and internal resistance $r.$ When this battery is connected to an external resistance of $2\ ohm,$ a current of $1\ amp.$ flows in the circuit. How much current will flow if the terminals of the battery are connected directly
A) $1\ amp$
B) $2\ amp$
C) $4\ amp$
D) Infinite
Explanation
(b) $i = \frac{E}{R + r} \Rightarrow 1 = \frac{4}{2 + r} = r = 2\Omega$
Short circuit, is when terminals of battery are connected directly, then current which flows is $
$$i_{SC} = \frac{E}{r} = \frac{4}{2} = 2A$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.