Download App

4. Moving charges and magnetism — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics4. Moving charges and magnetism1 Mark
MCQ
A square loop $ABCD$, carrying a current $i,$ is placed near and coplanar with a long straight conductor $XY$ carrying a current $I,$ the net force on the loop will be
  • ✓
    $\frac{{2{\mu _0}Ii}}{{3\pi }}$
  • B
    $\frac{{{\mu _0}Ii}}{{2\pi }}$
  • C
    $\frac{{2{\mu _0}Ii{\rm{l}}}}{{3\pi }}$
  • D
    $\frac{{{\mu _0}Ii{\rm{l}}}}{{2\pi }}$
✓

Answer

Correct option: A.
$\frac{{2{\mu _0}Ii}}{{3\pi }}$
a
Force on arm $AB$ due to current in conductor $- XY$ is

$F_{1}=\frac{\mu_{0}}{4 \pi} \frac{2 l i L}{(L / 2)}=\frac{\mu_{0} I i}{\pi}$

acting towards $-17$ in the plane of loop.

Force on arm $CD$ due to current in conductor $XY$ is

$F_{2}=\frac{\mu_{0}}{4 \pi} \frac{2 I i L}{3(L / 2)}=\frac{\mu_{0} I i}{3 \pi}$

acting away from $-ill$ in the plane of loop.

$\therefore$ Net force on the loop $=F_{1}-F_{2}$

$=\frac{\mu_{0} I i}{\pi}\left[1-\frac{1}{3}\right]=\frac{2}{3} \frac{\mu_{0} I i}{\pi}$

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 4. Moving charges and magnetism→4. Moving charges and magnetism — all question types→Physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

In scattering experiment, $\alpha$-particles scattered due to which force :
→
A current i ampere flows in a circular arc of wire whose radius is R, which subtend an angle 3π/2 radian at its centre. The magnetic induction B at the centre is
→
The total charge induced in a conducting loop when it is moved in magnetic field depends on
→
In a radioactive decay, neither the atomic number nor the mass number changes. Which of the following particles is emitted in the decay?
→
n equal resistors are first connected in series and then connected in parallel. What is the ratio of the maximum to the minimum resistance
→
Some radioactive nucleus may emit
→
Six charges, three positive and three negative of equal magnitude are to be placed at the vertices of a regular hexagon such that the electric field at O is double the electric field when only one positive charge of same magnitude is placed at R. Which of the following arrangements of charges is possible for P, Q, R, S, T and U respectively
→
A proton and an electron are accelerated by the same potential difference. Let $\lambda_\text{e}$ and $\lambda_\text{p}$ denote the de Broglie wavelengths of the electron and the proton respectively.
→
A loop of irregular shape carrying current is located in an external magnetic field. If  wire is flexible it will take the shape of
→
In Gallilean telescope, if the powers of an objective and eye lens are respectively $+1.25\, D$ and $-20 \,D$, then for relaxed vision, the length and magnification will be
→