Question

A 8 ohm resistance wire is stretched to double its length the new resistance of a wire will be

Answer 1

When a wire is stretched, its volume will remain the same.

Since Volume = Area x length, given that length has increased two times, the area will be halved.

So, new length = 2L. New Area = A/2

Resistance is proportional to Length/Area.

New resistance is proportional to 2L/(A/2)

New resistance = 4R

Thus resistance increases by 4













I have told u the process.Thecrest u do yourself.