Electric Current, Drift Velocity and Ohm's Law

A conductor carries a current of $50 \mathrm{\mu A}$. If the area of cross-section of the conductor is $50 {\mathrm{mm}}^2\text{,}$ then the value of the current density in $\mathrm{A} {\mathrm{m}}^{-2}$ is

Calculate mean free path in $Cu$ at room temperature $300 \mathrm{K}\text{,}$ if number density of free electrons is $8.5\times {10}^{28} {\mathrm{m}}^{-3}$ and resistivity $\mathrm{\rho }=1.7\times {10}^{-8} \mathrm{ohm} \mathrm{m}$. Given $\mathrm{k}=1.38\times {10}^{-23} {\mathrm{m}}^2 \mathrm{kg} {\mathrm{s}}^{-2} {\mathrm{K}}^{-1}$.

Nichrome or Manganin is widely used in wire bound standard resistors because of their

We are able to obtain fairly large currents in a conductor because

Drift velocity of electrons is due to

Mobilities of electrons and holes in a sample of intrinsic germanium at room temperature are $0.36 {\mathrm{m}}^2 {\mathrm{V}}^{-1} {\mathrm{s}}^{-1}$ and $0.17 {\mathrm{m}}^2 {\mathrm{V}}^{-1} {\mathrm{s}}^{-1}\text{.}$ The electron and hole densities are each equal to $2.5\times {10}^{19} {\mathrm{m}}^3\mathit{.}$ The electrical conductivity of germanium is

Calculate the drift velocity of electrons in silver wire with cross-sectional area $3.14\times {10}^{-6} {\mathrm{m}}^2$ carrying a current of $20 \mathrm{A}$. Given the atomic weight of $\mathrm{Ag}=108\text{,}$ density of silver $=10.5\times {10}^3 \mathrm{kg} {\mathrm{m}}^{-3}$.

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

The electron drift speed is small and the charge of the electron is also small but still, we obtain a large current in a conductor. This is due to

Current of $4.8$ amperes is flowing through a conductor. The number of electrons per second will be

Charge passing through a conductor of cross-section area $\mathrm{A}=0.3 {\mathrm{m}}^2$ is given by $q=3t^2+5t+2$ in coulomb, where $t$ is in seconds. What is the value of drift velocity at $\mathrm{t}=2 \mathrm{s}?$ (Given, $n=2\times {10}^{25} {\mathrm{m}}^{-3}$)