If electric current is passed through the metals to be joined and heated to the plastic state and weld is completed by the application of pressure, the welding is known as Resistance welding.

In resistance welding processes no fluxes are employed, the filler metal is rarely used and the joints are usually of the lap type. The amount of heat generated in the work-piece depend on the following factors:

●Magnitude of the current,

●Resistance of the current conducting path, and

Mathematically, H= IVt

= I(IR)t

= I²Rt

Where H = heat generated in joules

I = current in Amp.

R = resistance in ohms

t = time of current flow in seconds.

Hence, the correct option is (C).