A metallic conductor has a current of 5A flowing through it. The free electron density is $8.5 imes 10^{28} m^{-3}$. The cross-sectional area of the conductor is $2 imes 10^{-6} m^2$. If the average relaxation time is $2 imes 10^{-14} s$ and the electric field strength inside the conductor is 2 V/m, what is the mass of an electron (approximately)? (Assume the charge of an electron is $1.6 imes 10^{-19} C$).

On increasing the temperature of a conductor, its resistance increases because the

How much current should be passed through a silver voltmeter to deposit ${\rm{200}}\,\,{\rm{gm}}$ of silver per hour on the cathode? (Faraday constant $= 96500\;\,\,C/mol$ and relative atomic mass of silver is ${\rm{108}}$)

Assume that each atom of copper contributes one free electron. What is the average drift velocity of conduction electrons in a copper wire of cross-sectional area ${10^{ - 7}}\,\,{{\rm{m}}^2}$, carrying a current of ${\rm{1}}{\rm{.5}}\,{\rm{ A}}$ ? (Given density of copper $9\,\, imes \,\,{10^{ - 3}}\,\,{\rm{kg}}{{\rm{m}}^{ - 3}}$; atomic mass of copper ${\rm{ = }}\,{\rm{63}}{\rm{.5}}$; Avogadro’s number $= 6.023\,\, imes \,\,{10^{23}}$ per gram atom)

A conductor wire having ${10^{29}}$ free ${\rm{electrons}}\,\,/\,\,{{\rm{m}}^3}$ carries a current of ${\rm{20}}\,{\rm{A}}$. If the cross-section of the wire is $1\,\,{\rm{m}}{{\rm{m}}^2}$, then the drift velocity of electrons will be

The current flowing in a copper voltmeter is $3.2\,\,A$. The number of copper ions $\left( {C{u^{2 + }}} \right)$ deposited at the cathode per minute is

The maximum current that flows through a fuse wire before it blows out varies with its radius as

Electroplating does not help in

A metal wire is subjected to a constant potential difference. When the temperature of the metal wire increases, the drift velocity of the electron in it

When a charged particle of charge $e$ revolves in circular orbit of radius $r$ with frequency $n$, then orbital current will be

A piece of metal weighing ${\rm{200}}\,\,{\rm{ g}}$ is to be electroplated with ${\rm{5}}\,\,{\rm{\% }}$ of its weight in gold. How long it would take to deposits the required amount of gold, if the strength of the available current is ${\rm{2}}\,\,{\rm{A}}$ ? (Given, electrochemical equivalent of $H = 0.0104\,\, imes \,\,{10^{ - 4}}\,\,{\rm{g}}\,{{\rm{C}}^{ - 1}}$ atomic weight of gold = ${\rm{197}}{\rm{.1}}$, atomic weight of hydrogen = ${\rm{1}}{\rm{.008}}$ )