A battery you buy at the store has an internal emf of $3.0 \mathrm {~V}$. If it has an internal resistance of $14.0 \Omega$, what current will this battery put out if it is short-circuited?
A) $0.21 \mathrm {~A}$
B) $4.7 \mathrm {~A}$
C) $42 \mathrm {~A}$
D) $130 \mathrm {~A}$

Question

Quizplus · Accepted Answer

The current can be calculated using Ohm's Law, $I = \frac{V}{R}$, where $V = 3.0 \mathrm{~V}$ is the emf of the battery and $R = 14.0 \Omega$ is the internal resistance. Thus, $I = \frac{3.0}{14.0} = 0.214 \approx 0.21 \mathrm{~A}$.

A Battery You Buy at the Store Has an Internal 3.0 V3.0 \mathrm {~V}3.0 V

A Battery You Buy at the Store Has an Internal $3.0 \mathrm {~V}$