Question

A conducting loop of area 1 m² is placed normal to a uniform magnetic field of 3 Wb/m². If the magnetic field is uniformly reduced to 1 Wb/m² in 0.5 second, calculate the induced emf produced in the coil.

Answer 1

Given: A = 1 m²

B_i = 3 Wb/m²

B_f = 1 Wb/m²

dt = 0.5 s

Total Initial flux (Φ_i) = B_iA

= 3 × 1

= 3 Wb

Total final flux (Φ_f) = B_fA

= 1 × 1

= 1 Wb

Induced e.m.f. (e) = `- (d phi)/dt`

= `-(phi_f - phi_i)/dt`

= `-(1 - 3)/0.5`

= `2/0.5`

= 4 V