Question

Two wires of copper and other of magnesium are equal lengths and equal resistance which wire is thicker

Answer 1

The thickness of the copper wire is more because the conductivity of copper is more than the conductivity of magnesium they means the resistance of copper wire is less than the magnesium wire. To get less resistance the thickness of the magnesium wire must be decreased much more than the copper wire.

I hope this answer helps you a lot.