Three copper rods are subjected to different potential difference… - Vidyadip

MCQ

Three copper rods are subjected to different potential difference. Compare the drift speed of electrons through them. Assume that all $3$ are at the same temperature.

	Length	Diameter	Potential difference
$(A)$	$L$	$3d$	$V$
$(B)$	$2L$	$d$	$2V$
$(C)$	$3L$	$2d$	$2V$

✓
$v_A = v_B > v_C$
B
$v_A > v_B > v_C$
C
$v_A < v_B < v_C$
D
None of these

✓

Answer

Correct option: A.

$v_A = v_B > v_C$

a
$\mathrm{i}=\mathrm{neAV}_{\mathrm{drift}}=\frac{\mathrm{V}}{\mathrm{R}}$

$\mathrm{R}=\frac{\rho \ell}{\mathrm{A}}=\frac{4 \rho \ell}{\pi \mathrm{d}^{2}}$

$\therefore {{\rm{V}}_{{\rm{drift}}}} = \frac{{\rm{V}}}{{{\rm{RneA}}}} = \frac{{\rm{V}}}{{\frac{{\rho \ell }}{{\rm{A}}} \times {\rm{neA}}}} = \frac{{\rm{V}}}{{\rho \ell {\rm{ne}}}} \propto \frac{{\rm{V}}}{\ell }$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 3. current electricity→3. current electricity — all question types→Physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

The plot given below is of the average power delivered to an $LRC$ circuit versus frequency. The quality factor of the circuit is

Two coaxial solenoids 1 and 2 of the same length are set so that one is inside the other. The number of turns per unit length are $n_1$ and $n_2$. The currents $i_1$ and $i_2$ are flowing in opposite directions. The magnetic field inside the inner coil is zero. This is possible when

The ratio of charge to potential of a body is known as

A capacitor of capacitance $100\ \mu \mathrm{F}$ is charged to a potential of $12 \mathrm{~V}$ and connected to a $6.4 \ \mathrm{mH}$ inductor to produce oscillations. The maximum current in the circuit would be :

The number of turns in primary and secondary coils of a transformer are 100 and 20 respectively. If an alternating potential of 200 volt is applied to the primary, the induced potential in secondary will be

The given transistor operates in saturation region then what should the be value of $V _{ BB }$ (in $Volt$)

$( R _{\text {out }}=200 \Omega, R _{\text {in }}=100 k \Omega,$$ V _{ cC }=3 volt , V _{ BE }=0.7 volt ,V _{ GE }=0, \beta=200 )$

While working on a physics project at school physics lab, you require a $4 \,\mu F$ capacitor in a circuit across a potential difference of $1 \,kV$. Unfortunately, $4 \,\mu F$ capacitors are out of stock in your lab but $2 \,\mu F$ capacitors which can withstand a potential difference of $400 \,V$ are available in plenty. If you decide to use the $2 \,\mu F$ capacitors in place of $4 \,\mu F$ capacitor, minimum number of capacitors required are

When a straight wire is moved up and down rapidly between two poles of a horseshoe magnet then $.......$ is produced in the wire.

Which one of the following is feebly repelled by a magnet?

The resistive network shown below is connected to a $D.C.$ source of $16\, V$. The power consumed by the network is $4\, Watt$. The value of $R$ is ............. $\Omega$