A conducting circular loop is placed in a uniform magnetic field, B = 0 . 025 T with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of 1 mm s - 1 . The induced emf when the radius is 2 cm , is

Step-by-step solution

Here, magnetic field, B = 0 . 025   T ∴ Magnetic flux ϕ = B · A = B · π r 2 Induced emf   e = d ϕ d t = B π 2 r · d r d t = 0 . 025 × π × 2 × 2 × 10 - 2 × 1 × 10 - 3 = π × 10 - 6     V = π   μV