Question

The emf induced when a magnet moves towards a stationary coil is $e$. If the coil is also moved towards the magnet with the same speed, then the induced emf is _________.

• A. $e$
• B. $\frac{e}{2}$
• C. $2e$
• D. $e^2$

Answer 1

The correct option is C $2e$

$inducedEMF=velocity\ast lenght\ast Magneticfield$

The emf induced when a magnet moves towards a stationary coil is $e$.

$e=v\ast L\ast B$

but when the coil is also moved towards the magnet with the same speed,

The relative velocity is $v_r=v-(-v)=2v$

$e_1=\left(2v\right)LB=2vLB=2eVolt$