Question

how does the resistance of a conductor change with the change in its area of cross section explain in about 50 words

Answer 1

The device which is used to measure the potential difference between two points is voltmeter. It's always connected in parallel with the circuit.

Answer 2

Tje resistance of a conductor R is inversely proportional to its area of cross section A.
since the resistance of a wire is inversely proportional to its area of cross section when the area of cross section of wire is doubled, then its resistance gets halved and if area of cross section of wire is halved then its resistance will get doubled.