A given length of a wire is doubled on itself and this process is repeated once again .By what factor does the resistance of the wire changes? give reason by solving.

If the length of wire is drawn to double its length then length has increased double and area get reduced to helf

 

So, Resitance will be 4 times.

 

And, again the process is repeated so resitance will increase 4 times. So tallay, the resitance get increased by 16 times.