A battery is rated such that it provides $1.0 \mathrm {~mW}$ of power at $9.0 \mathrm {~V}$ when fully charged.How much current can it deliver?
A)0.11 mA
B)81 kA
C)0.33 mA
D)9.1 kA

Question

Quizplus · Accepted Answer

The current delivered by the battery can be calculated using Ohm's law: $I = V/R$. Since the battery provides $1.0 \mathrm {~mW}$ of power at $9.0 \mathrm {~V}$, the resistance of the battery is:$$R = V^2/P = (9.0 \mathrm {~V})^2/(1.0 \mathrm {~mW}) = 81 \mathrm {~k\Omega}$$Therefore, the current delivered by the battery is:$$I = V/R = 9.0 \mathrm {~V}/81 \mathrm {~k\Omega} = 0.11 \mathrm {~mA}$$

A Battery Is Rated Such That It Provides 1.0 mW1.0 \mathrm {~mW}1.0 mW

A Battery Is Rated Such That It Provides $1.0 \mathrm {~mW}$