Question

A magnet is moved towards a coil (i) quickly (ii) slowly, then the induced charge is

• A. larger in case (i)
• B. smaller in case (i)
• C. equal to both cases
• D. larger or smaller depending upon radius of the coil

Answer 1

The correct option is A larger in case (i)

The emf induced in a coil is equal to rate of change of flux through the coil.

$EMF=-\frac{d\varphi }{dt}$

When magnet moves quickly, the rate of change of flux through the coil is also greater and hence induced charge is greater.