Question

A coil of area 100 cm² is kept at an angle of 30° with a magnetic field of 10⁻¹ T. The magnetic field is reduced to zero in 10⁻⁴ s. The induced emf in the coil is ______.

Options

• `5sqrt3  V` 

• `50 sqrt3  V` 

• 5.0 V

• 50.0 V

Answer 1

A coil of area 100 cm² is kept at an angle of 30° with a magnetic field of 10⁻¹ T. The magnetic field is reduced to zero in 10⁻⁴ s. The induced emf in the coil is `bbunderline(5sqrt3  V` ).

Explanation:

Flux through the coil θ = BAcos θ

or, Φ = 10−1 × (100 × 10−4) × cos 30°

∴ ` phi = 10^(−3) xx sqrt(3//2)` Wb

Induced emf = ε

= `(-dphi)/dt`

= `(-(phi_f - phi_i))/(Delta t)`

= `[-(0 - 10^(-3) xx sqrt3/2)]/(10^(-4))`

= `5 sqrt3` V