A silver wire of radius $$0.1 \mathrm{~cm}$$ carries a current of $$2 \mathrm{~A}$$. If the charge density in silver is $$5.86 \times 10^{28} \mathrm{~m}^{-3}$$, the drift velocity is

An electron revolves in a circle at the rate of $$10^{19}$$ rounds per second. The equivalent current is $$\left(e=1.6 \times 10^{-19} \mathrm{C}\right)$$

The temperature coefficient of the resistance of a wire is 0.00125 per $${ }^{\circ} \mathrm{C}$$. At $$300 \mathrm{~K}$$ its resistance is $$1 \Omega$$. The resistance of wire will be $$2 \Omega$$ at