Question

A wire has resistance of 8 ohm . If its length is made half by folding, find its resistance after the free ends are connected to each other?

Answer 1

Resistance R = 8 ohm
let's take length as L
and cross section area as A

here we need to use the formula R= rho(L/A)
here rho (as i didn't find the Greek symbol for it) stands for resistivity

as length is halved and r the radius is increased by two
R is reduced to R/4=8/4=2 ohm

so new resistance will be  2 ohm