Question

if the potential difference between the ends of fixed resistor is halved, the electric power will become

Answer 1

Potential difference is actually the the difference of the electrical pressure between the two terminals of an electronic circuit or any sort of electrical resistor.

We generally calculate the numerical value of the potential difference by applying the Ohm's law.

And according to the Ohm's law electrical power will be doubled if the potential difference becomes half then it's previous value.