-
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 e.m.f. when the radius is 2 cm, is
-
- 2πμ V
- πμ V
-
π μ V 2 - 2μ V
Correct Option: B
Magnetic flux linked with the loop is
φ = Bπr2
| |e| = | = B π .2r | |||
| dt | dt |
When r = 2 cm,
| = 1 mm s-1 | dt |
e = 0.025 × π × 2 × 2 × 10–2 × 10–3
= 0.100 × π × 10–5 = π × 10–6 V = π μ V
