Acopper ring and a wooden ring of the same dimensions are placed in magnetic fields so that there is the same change in magnetic flux through them. compare the induced emfs and currents in the rings.

emf induces in both iron and copper is same

Explanation:

The induced emf in both the rings would be same.

The induced emf in any material is given by

N= number of turns in the coil

dΦ= change in magnetic flux

dt= change in time

clearly, induced emf is independent of the material of the object,it only depends upon rate of change of flux.

therefore, emf induces in both iron and copper is same.

i think its c if i'm wrong

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j