$$I-V$$ characteristic of a copper wire of length $$L$$ and area of cross-section $$A$$ is shown in figure. The slope of the curve becomes

The readings of ammeter and voltmeter in the following circuit are respectively

Though the electron drift velocity is small and electron charge is very small, a conductor can carry an appreciably large current because

Masses of three wires of copper are in the ratio $$1: 3: 5$$ and their lengths are in the ratio $$5: 3: 1$$. The ratio of their electrical resistance are