Questions in Current Electricity

Select	Question
	If the resistance of a conductor is $5 \Omega$ at $50^oC$ and $7 \Omega$ at $100^oC$ then the mean temperature coefficient of resistance of the material is
	The resistance of a discharge tube is
	We are able to obtain fairly large currents in a conductor because
	A platinum resistance thermometer has a resistance of 50 ohm at $20^\circ C$. When dipped in a liquid the resistance becomes $76.8\,\Omega$. The temperature coefficient of resistance for platinum is $\alpha = 3.92 \times {10^{ - 3}}/^\circ C$. The temperature of the liquid is
	In a wire of circular cross-section with radius r, free electrons travel with a drift velocity V when a current I flows through the wire. What is the current in another wire of half the radius and of the same material when the drift velocity is 2V
	The resistivity of a wire depends on its
	The conductivity of a superconductor is
	In a neon discharge tube $2.9 \times {10^{18}}\,N{e^ + }$ ions move to the right each second while $1.2 \times {10^{18}}$ electrons move to the left per second. Electron charge is $1.6\times10^{-19}C$. The current in the discharge tube
	A steady current flows in a metallic conductor of non-uniform cross-section. The quantity/ quantities constant along the length of the conductor is/are,Current
	The resistivity of alloys $ = {R_{{\rm{alloy}}}}$; the resistivity of constituent metals $R_{\mathrm{metal}}$. Then, usually