let's see how the Faraday's law works. when the bar magnet is static
No flux changes across the coil. Induced voltage across the coil is zero.The bulb
does not glow.
now flux is changing across the coil so
bulb is glowing here. The induced voltage
in the coil also depends on the number of
turns in the coil.  Here is a four turn coil.
Upper one is two turns coil. so induced voltage here must be greater than the two turns coil. Now
see the bulb glows lesser than the two turns coil. That's all.
Thank you.
