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 $1.6 imes 10^{-19} C$).

The current flowing in a copper voltmeter is ${\rm{1}}{\rm{.6}}\,\,{\rm{A}}$. The number of $C{u^{ + + }}$ ions deposited at the cathode per minute are

The relation between Faraday’s constant $F$, electron charge $e$ and avogadro number $N$ is

The density of copper is $9\,\, imes \,\,{10^3}\,\,{\rm{kg}}/{{\rm{m}}^3}$ and its atomic mass is ${\rm{63}}{\rm{.5}}\,\,{\rm{u}}$. Each copper atom provides one free electron. Estimate the number of free electrons per cubic metre in copper.

The relation between Faraday’s constant $F$, electron charge $e$ and avogadro number $N$ is

Every atom makes one free electron in copper. If ${\rm{1}}{\rm{.1 }}\,{\rm{A}}$ Current is flowing in the wire of copper having ${\rm{1 mm}}$ diameter, then the drift velocity(approx.) will be (density of copper = $9\,\, imes \,\,{10^3}\,\,{\rm{k}}\,{\rm{g}}{{\rm{m}}^{ - 3}}$ and atomic weight of copper =${\rm{63}}$)

The current flowing in a copper voltmeter is ${\rm{1}}{\rm{.6}}\,\,{\rm{A}}$. The number of $C{u^{ + + }}$ ions deposited at the cathode per minute are

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

If ${\rm{2}}\,\,{\rm{A}}$ of current is passed through ${\rm{C}}\,{\rm{u}}\,{\rm{S}}\,{{\rm{O}}_4}$ solution for ${\rm{32}}\,\,{\rm{s}}$, then the number of copper ions deposited at the cathode will be

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)

Current is flowing with a current density $J = 480\,\,{\rm{A}}\,{\rm{c}}{{\rm{m}}^{ - 2}}$ in a copper wire. Assuming that each copper atom contributes one free electron and given that Avogadro number $= 6.0\,\, imes \,\,{10^{23}}\,\,{\rm{atoms}}\,\,{\rm{mo}}{{\rm{l}}^{ - 1}}$

Density of copper$= \,\,9.0\,{\rm{g}}\,\,{\rm{c}}{{\rm{m}}^{ - 3}}$

Atomic weight of copper ${\rm{ = }}\,{\rm{64}}\,{\rm{g}}\,\,{\rm{mo}}{{\rm{l}}^{ - 1}}$

The drift velocity of electrons is