NEET Physics MCQ: NCERT Current Electricity

🎓 Ncert Level:Understanding

🔄Ncert Concepts :Drift velocity, Thermal velocity, Temperature dependence of resistance, Ohm's Law

Related Questions

In cosmic rays ${\rm{0}}{\rm{.15}}$ protons ${\rm{c}}{{\rm{m}}^{ - 2}}\,\,{\sec ^{ - 1}}$ ⁡ are entering the earth’s atmosphere. If the radius of the earth is ${\rm{6400}}\,{\rm{ km}}$ , the current received by the earth in the form of cosmic rays is nearly.

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{{\rm{0}}{\rm{.12}},,{\rm{A}}}

\end{array}$

$\begin{array}{*{20}{l}}

{{\rm{1}}{\rm{.2}},,{\rm{A}}}

\end{array}$

$\begin{array}{*{20}{l}}

{{\rm{12}},,{\rm{A}}}

\end{array}$

$\begin{array}{*{20}{l}}

{{\rm{120}},,{\rm{A}}}

\end{array}$

Question Tags

⚡ Time Required :3 mins

🔄Ncert Concepts :Area of a sphere, Current, Proton charge

The electron of hydrogen atom is considered to be revolving round in circular orbit of radius ${h^2}/m{e^2}$ with velocity $\frac{{{e^2}}}{h}$ , where $h = h/2\pi$ . The current i is

$\frac{{4\,{\pi ^2}\,m{e^5}}}{{{h^2}}}$

$\frac{{4\,{\pi ^2}\,m{e^2}}}{{{h^3}}}$

$\frac{{4\,{\pi ^2}\,{m^2}\,{e^5}}}{{{h^3}}}$

$\frac{{4\,{\pi ^2}\,m\,{e^5}}}{{{h^3}}}$

Question Tags

⚡ Time Required :3 mins

🔄Ncert Concepts :Current, Circular Motion, Charge of electron, Planck's Constant, Velocity

If the electric current through an electric bulb is ${\rm{3}}{\rm{.2 }}\,{\rm{A}}$ , the number of electrons flow through it in one second is

$2\,\, imes \,\,{10^9}$

$2{\mkern 1mu} {\mkern 1mu}  imes {\mkern 1mu} {\mkern 1mu} {10^{19}}$

$3.2\,\, imes \,\,{10^{19}}$

$1.6\,\, imes \,\,{10^{18}}$

Question Tags

🔄Ncert Concepts :electric current, charge, number of electrons, elementary charge

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

$6.25\,\, imes \,\,{10^{ - 3}}\,\,{\rm{m}}{{\rm{s}}^{ - 1}}$

$1.25\,\, imes \,\,{10^{ - 5}}\,\,{\rm{m}}{{\rm{s}}^{ - 1}}$

$1.25\,\, imes \,\,{10^{ - 3}}\,\,{\rm{m}}{{\rm{s}}^{ - 1}}$

$1.25\,\, imes \,\,{10^{ - 4}}\,\,{\rm{m}}{{\rm{s}}^{ - 1}}$

Question Tags

🔄Ncert Concepts :Current, Drift velocity, Electron density, Area

When the current $i$ is flowing a conductor, the drift velocity is $v$ . If $2i$ current is flowed through the same metal but having double the area of cross-section, then the drift velocity will be

$v/4$

$v/2$

$v$

$4v$

Question Tags

🔄Ncert Concepts :current, drift velocity, charge density, area of cross-section

A conductor of cross-sectional area $1 imes 10^{-6} m^2$ carries a current of 4A. If the number density of free electrons is $10^{28} m^{-3}$ , and the charge on an electron is $1.6 imes 10^{-19} C$ , what is the magnitude of the drift velocity of the electrons, assuming they all contribute to the current?

2.5 x 10^-3 m/s

2.5 x 10^-2 m/s

6.4 x 10^-1 m/s

6.4 x 10^-2 m/s

Question Tags

🎯Difficulty :Hard

🔄Ncert Concepts :Electric Current, Drift Velocity, Current Density

The current in a wire is 2 A. How many electrons pass a given point in the wire in 10 seconds? (Charge of an electron = $1.6 imes 10^{-19} C$ )

6.25 x 10^18 electrons

1.25 x 10^20 electrons

2.5 x 10^19 electrons

3.2 x 10^20 electrons

Question Tags

🎯Difficulty :Easy

⚡ Time Required :1 mins

🔄Ncert Concepts :Electric Current, Charge, Electron

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

$6.25\,\, imes \,\,{10^{ - 3}}\,\,{\rm{m}}{{\rm{s}}^{ - 1}}$

$1.25\,\, imes \,\,{10^{ - 5}}\,\,{\rm{m}}{{\rm{s}}^{ - 1}}$

$1.25\,\, imes \,\,{10^{ - 3}}\,\,{\rm{m}}{{\rm{s}}^{ - 1}}$

$1.25\,\, imes \,\,{10^{ - 4}}\,\,{\rm{m}}{{\rm{s}}^{ - 1}}$

Question Tags