Question

A 10 ohm resistance wire is doubled on it. Calculate the new resistance of the wire.

Answer 1

Answer:2.5 ohm

Explanation:

R= ρl/A

If resistance get doubled, length of the wire halved and area of cross section will be doubled.

i.e,

R=ρ(l/2)÷2A = ρl/4A = 1/4*R

If ρl/A= 10 (by question),

New resistance = 10/4 = 2.5 ohm