Question

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 the ratio R/R` is-? ​

Answer 1

since the wire is cut into five equal pieces

R=5r (in series) --(eq1)

where r is the resistance of each piece of the wire and R is the resistance of the wire before cutting it

now 1/R'=5(1/r) (in parallel) --(eq2)

eq1×eq2

R/R'=5r×5/r=25:1

Answer 2

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 the ratio R/R` is

25:1