Question

The magnetic flux that passes through one turn of a 8-turn coil of wire changes to 5.0 Wb from 8.0 Wb in a time of 0.098 s. The average induced current in the coil is 140 A. What is the resistance of the wire

Answer 1

Answer:

Resistance is 1.75 ohms

Explanation:

Magnetic flux:

${ \phi{ = NBA}}$

N is number of turns, N = 8

B is magnetic flux

A is area of projection.

From faradays law:

$E = - \frac{ \triangle \phi}{t}$

where E is the Electro motive force.

But E = IR

where I is current and R is resistance:

$IR = \frac{( \phi_{1} - \phi _{2}) }{t} \\ \\ 140 \times R = \frac{8 \times (8 - 5)}{0.098} \\ \\ R = \frac{24}{0.098 \times 140} \\ \\ resistance = 1.75 \: ohms$