Question

current i flows through a conductor connected across a voltage source. now the resistance is reduced to 1/2 .the heating effect in the conductor will become?

Answer 1

Heating effect in the Ist case is given by :
H = I² R t
where I is the current through the conductor and R is the resistance.
In the IInd case :
R' = R/2
So, H' = I² (R/2) t = H/2