Name three factors on which resistance of a given wire depends and state how it is affected by the factors stated by you?

(a) Name two factors on which the specific resistance of a wire depends?

(b) Two wires A and B are made of copper. The wire A is long and thin while the wire B is short and thick. Which will have more specific resistance?

How does the specific resistance of a semi-conductor change with the increase in temperature?

Two wires, one of copper and other of iron, are of the same length and same radius. Which will have more resistance? Give reason.