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

Two wire of copper have length L and 2L and cross section 2A and A respectively .The ratio of their specific resistance would be would be

Two wires made from the same material have their lengths L and 2L and the radii 2r and r respectively. What is the ratio of their elongation if they are stretched by the same force ?

Two wires of same material have length L and 2 L and cross– sectional areas 4 A and A respectively. The ratio of their specific resistance would be

Two wires of the same material and same length have radii 1 mm and 2 mm respectively. Compare : their specific resistance.

Two copper wires A and B of length 30 m and 10 m have radii 2 cm and 1 cm respectively. Compare the resistances of the two wires. Which will have less resistance ?