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AP® Physics C: E & M

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Moderate

Resistivity and Power

APPHEM-87R8Y6

An electrical wire has a power rating of $5 \text { } \mathrm W$. The length of the wire is $1 \text { } \mathrm {cm}$ and the radius is $0.001 \text { } \mathrm m$. The wire is made of copper which has a resistivity of $\rho = 1.72 \times 10^{-8} \text { } \mathrm {\Omega \cdot m}$. What is the maximum current, $I$, in Amps, that can flow through this length of wire?

A

$0.0033 \text { } \mathrm A$

B

$9.6 \text { } \mathrm A$

C

$302 \text { } \mathrm A$

D

$5392 \text { } \mathrm A$

E

$91279 \text { } \mathrm A$