Question

A 30-turn coil has a diameter of 11 cm. The coil is placed in a spatially uniform magnetic field of magnitude 0.30 T so that the face of the coil and the magnetic field are perpendicular. Find the magnitude of the emf induced in the coil (in V) if the magnetic field is reduced to zero uniformly in the following times. (a) 0.70 s

Answer 1

The magnitude of induced emf is 0.122 V

Step-by-step explanation:

Given:

Number of turns
`N = 30`

Magnetic field
`B = 0.30` T

Radius of coil
`r = (d)/(2) = 5.5 * 10^(-2)` m

Change in time
`dt = 0.70` sec

For finding the magnitude of induced emf,

According to the faraday's law,

`\epsilon = -N (d\phi)/(dt)`

Where
`\phi =` magnetic flux

`\phi = BA`

Where
`A = \pi r^(2)` area of coil

For finding magnitude we neglect minus sign,

`\epsilon = N (B\pi r^(2) )/(dt)`

`\epsilon = (30 * 0.30 * 3.14 * (5.5 * 10^(-2) )^(2) )/(0.70)`

`\epsilon = 0.122` V

Therefore, the magnitude of induced emf is 0.122 V