Question

A conductor of resistance 10 ohm is stretch to twice it's length. Find its resistance

Answer 1

For a cylindrical conductor the resistance is directly
proportional to the length of the conductor and the
resistance is inversely proportional to the area of the
conductor that is resistance is inversely proportional to
the square of the radius of the cylindrical conductor.
If it is stretched so that its length is doubled without c
hanging its volume





R₂₌4R₁


As the initial resistance is 10 ohm
The resistance of the wire which is drawn out so that
its length is increased to twice its original length

is R₂ = 4⨯10 Ω ⇒ R₂ = 40 Ω