Question

if the area of the cross section of a wire gets half and length Doubles what will be the effect on the resistance​

Answer 1

Answer:

Hence Resistance will become 4 times in the new condition, if the area is doubled and length is halved.

Answer 2

Resistivity is directly proportional to area of cross-section and inversely proportional to length.

In this case area of cross section is halved and length is doubled

i.e., R x a

R x 1/l

ATQ,

R x a/2 and R x 1/2l

R = a/2 x 1/2l

this means that the resistivity will reduce by 1/4 th.