Question

A magnetic field of 2 x 10^-2 T acts at right angles to a coil of area 50 cm² with 100 turns. The average e.m.f. induced in the coil is 0.2 V, when it is removed from the field in time t. The value of t is ____________.

Options

• 5 x 10^-3 s

• 5 x 10^-2 s

• 5 x 10^-4 s

• 5 x 10^-5 s

Answer 1

A magnetic field of 2 x 10^-2 T acts at right angles to a coil of area 50 cm² with 100 turns. The average e.m.f. induced in the coil is 0.2 V, when it is removed from the field in time t. The value of t is 5 x 10^-2 s.

Explanation:

`"e" = - ("n"("B"_2 - "B"_1) "A cos" theta)/"t"`

`therefore "t" = (-100 xx (0 - 2 xx 10^-2) xx 50 xx 10^-4 xx cos 0°)/0.2`

`therefore "t" = 5 xx 10^-2  "s"`