A copper wire of length l and r radius r is nickel plated till its final radius is 2r. If the resistivity of the copper and nickel are `rho_(c)` and `rho_(n)`, then find the equivalent resistance of the wire.

A copper wire of length l and radius r is nickel plated till its final radius is 2r. If the resistivity of the copper and nickel are rho_(c) and rho_(n) , then find the equivalent resistance of the wire.

A copper wire of length l and radius r is nickel plated till its final radius is 2r. If the resistivity of the copper and nickel are rho_(c) and rho_(n) , then find the equivalent resistance of the wire.

Two metallic wires A and B are connected in parallel. Wire A has length l and radius r, wire B has a length 2 l and radius 2r. Compute the ratio of the total resistance of parallel combination and the resistance of wire A.

Two copper wire of length l and 2l have radii, r and 2r respectively. What si the ratio of their specific resistance.?

Two copper wire of length l and 2l have radii, r and 2r respectively. What si the ratio of their specific resistance.?

A given piece of wire of length l and radius r and resistance R is stretched uniformly to wire of radius (r)/(2) .Its new resistance is: