Question

The heat produced by passing an electric current through a fixed resistor is proportional to the square of:  

(a) magnitude of resistance of the resistor
(b) temperature of the resistor
(c) magnitude of current
(d) time for which current is passed

Answer 1

(c) magnitude of current      

We know that:
H = I²Rt

It shows that the heat produced is proportional to the square of the current.