A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R', then find the ratio `(R)/(R')`

Explanation

Resistance of a piece of length `(l)/(5)= (R)/(5)`
The equivalent resistance of the 5 wires in parallel is R.. Then
`(1)/(R.)= (1)/(R//5)+(1)/(R//5)+(1)/(R//5)+(1)/(R//5)+(1)/(R//5)`
`(1)/(R.)= (5)/(R)+ (5)/(R)+ (5)/(R)+ (5)/(R)+ (5)/(R)`
`(1)/(R.)= (25)/(R)`
`:. (R)/(R.)= 25`