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A narrow copper wire of length L and radius b is attached to a wide copper wire of length L and radius 2b, forming one long wire of length 2L. This long wire is attached to a battery, and a current is flowing through it. If the electric field in the narrow wire is E, the electric field in the wide wire is:______

a. E
b. 2E
c. 4E
d. E/2
e. E/4

Respuesta :

Answer:

Correct answer is E/4.

Explanation:ρ

by the formula of [tex]R=\frac{\rho L}{A}[/tex]

Now, [tex]R_{1} = \frac{\rho L}{\pi b^{2}} \\ R_{2} = \frac{\rho L}{4\pi b^{2}}[/tex]

and, [tex]R_{1}=4R_{2}[/tex]

The wires are connected in series so the current will be same. So, by the [tex]V=iR[/tex] formula

[tex]V_{1}=4{V_{2}[/tex]

similarly,

[tex]E_{1}=4E_{2}\\E=4E_{2}\\E_{2}=\frac{E}{4}[/tex]    

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