Question

A piece of wire of
resistance 20 owhm is drawn out so that its length is increased to twice its original length calculate the resistance of the wire in the new situation. ​

Answer 1

Answer:

R= rho X l/A -------(1)

Let length =2l

R'= rho X 2l /A

R'= 2(rhoX l/A)

Put the eq 1

R'= 2(R)

R'= 2X 20 = 40ohm