Resistance of a given wire of length 'L' is 2 ohm. The wire is stretched uniformly such that its length
becomes 3L. Find the new resistance of the stretched wire.
Solution -
Resistance is directly proportional to the length.
So,
r1/r2 = l1/ l2
2/ r2 = l / 3l,
2/ r2 = 1/ 3,
r2 = 2×3,
r2 =6 ohm
new resistance is 6 ohm.