(B) Given: Current $i = 10\, A$,Area $A = 5\, mm^{2} = 5 \times 10^{-6}\, m^{2}$,Drift velocity $v_{d} = 2 \times 10^{-3}\, m/s$,and charge of an elec

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(B) Given: Current $i = 10\, A$,Area $A = 5\, mm^{2} = 5 \times 10^{-6}\, m^{2}$,Drift velocity $v_{d} = 2 \times 10^{-3}\, m/s$,and charge of an electron $e = 1.6 \times 10^{-19}\, C$.We know the relation between current and drift velocity is $i = neAv_{d}$.Rearranging for the number density $n$,we get $n = \frac{i}{eAv_{d}}$.Substituting the values: $n = \frac{10}{1.6 \times 10^{-19} \times 5 \times 10^{-6} \times 2 \times 10^{-3}}$.$n = \frac{10}{16 \times 10^{-28}} = 0.625 \times 10^{28} = 625 \times 10^{25}\, m^{-3}$.

Class 12 Physics Current Electricity Current Density, Drift Velocity and Mobility

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$A$ current of $10\, A$ exists in a wire of cross-sectional area of $5\, mm^{2}$ with a drift velocity of $2 \times 10^{-3}\, m/s$. The number of free electrons in each cubic meter of the wire is ..........

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A
$2 \times 10^{6}$
B
$625 \times 10^{25}$
C
$2 \times 10^{25}$
D
$1 \times 10^{23}$

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Current Electricity

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Current Density, Drift Velocity and Mobility

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$A$ current of $5 \,A$ is passing through a metallic wire of cross-sectional area $4 \times 10^{-6} \,m^{2}$. If the density of charge carriers of the wire is $5 \times 10^{26} \,m^{-3}$, the drift velocity of the electrons will be:

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$A$ current of $10\, A$ exists in a wire of cross-sectional area of $5\, mm^{2}$ with a drift velocity of $2 \times 10^{-3}\, m/s$. The number of free electrons in each cubic meter of the wire is ..........

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In a particle accelerator,a current of $500 \,\mu A$ is carried by a proton beam in which each proton has a speed of $3 \times 10^7 \,m/s$. The cross-sectional area of the beam is $1.50 \,mm^2$. The charge density in this beam (in $C/m^3$) is close to

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The drift velocity of an electron is $v_d$ in a conductor of area of cross-section $A$ and carries a current $I$. Now,the area of cross-section and current flowing through the conductor are doubled,then the new drift velocity of the electron is . . . . . . .

$A$ current of $5 \,A$ is passing through a metallic wire of cross-sectional area $4 \times 10^{-6} \,m^{2}$. If the density of charge carriers of the wire is $5 \times 10^{26} \,m^{-3}$, the drift velocity of the electrons will be:

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