A uniform magnetic field is normal to the plane of a circular loop 10.4 cm in diameter made out of copper wire (diameter). (a) We have to calculate the resistance of the wire. (b) We have to find the rate at which the magnetic field must change with time if an induced current of 9.66 A has to appear in the loop.

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It is given that a uniform magnetic field is normal to the plane of a circular loop 10.04 cm in diameter.

We will first calculate the resistance of the copper wire.

Length of the wire,

Cross-sectional area of the wire,

Resistivity of copper,

Resistance of the wire,

From Faraday’s law, the electromotive force in a circuit due to changing magnetic flux is given by the expression

The induced current in the circuit,

As

we find