A wire of resistance R and radius r is stretched till its radius became r / 2 . If new resistance of the stretched wire is x R , then value of x is _______

Step-by-step solution

We know R = l ~A , R l r ^2 As we starch the wire, its length will increase but its radius will decrease keeping the volume constant aligned & V _ i = V _ f & r ^2 l= r ^2 4 l_ f & l_ f =4 l & R _ new R _ old = ( 4 l r ^2 4 ) r ^2 l =16 & R _ new =16 R & x =16 aligned