Question

A circular copper disc of radius 25 cm is rotating about its own axis with a constant angular velocity of 130 rad/s. If a magnetic field of 5 103 tesla is applied at right angles to the disc, then the induced potential difference between the centre and the rim of the disc will approximately be

Answer 1

Answer:

The length of the radius, l = 25 cm = 0.25 m

Angular velocity, ω = 130 rad/s

The magnetic field, B = 5 * 10³ T

Let the induced potential difference be denoted as “ε”.

Therefore,

The induced potential difference between the centre and the rim of the disc is given by  

ε = ½ * B * ω * l²

substituting the given values

or, ε = ½ * 5 * 10³ * 130 * (0.25)²

or, ε = ½ * 5 * 10³ * 130 * 0.0625 = 20.31 * 10³ V

Hence, the induced potential difference is 20.31 * 10³ V.