JEE Mains · Physics · STD 12 - Moving charges and magnetism
- JEE Mains 2019
- Hard
- MCQ
A rigid square loop of side \(a\) and carrying current \(I_2\) is laying on a horizontal surface near a long current \(I_1\) wire in the same plane as shown in figure. The net force on the loop due to the wire will be

Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) Repulsive and equal to \(\frac{{{\mu _0}{I_1}{I_2}}}{{4\pi }}\)
Step-by-step Solution
Detailed explanation
\({{\text{F}}_3}{\text{& }}{{\text{F}}_4}\,{\text{cancel}}\,{\text{each}}\,{\text{other}}{\text{. }}\)
\({\text{Force on PQ will be }}{{\text{F}}_1} = {2_B}{\text{Ia}}\)
\({\text{ = }}{{\text{I}}_2}\frac{{{\mu _0}{I_1}}}{{2\pi {\text{a}}}}{\text{a}}\)
\( = \frac{{{\mu _0}I}}{{2\pi {\text{a}}}}{\text{a}}\)
\( = \frac{{{\mu _0}{I_1}{I_2}}}{{2\pi }}\)
Force on \(RS\) will be \(F_{2}=I_{2} B_{2} a\)
\({=\mathrm{I}_{2} \frac{\mu_{0} \mathrm{I}_{1}}{2 \pi 2 \mathrm{a}} \mathrm{a}}\)
\({=\frac{\mu_{0} I_{1} I_{2}}{4 \pi}}\)
Net force \(=\mathrm{F}_{1}-\mathrm{F}_{2}=\frac{\mu_{0} I_1 \mathrm{I}_{2}}{4 \pi}\) repulsion
More questions from Physics
- A heat source at \(T = 10^3\, K\) is connected to another heat reservoir at \(T = 10^2\, K\) by a copper slab which is \(1\, m\) thick. Given that the thermal conductivity of copper is \(0.1\, WK^{-1}\, m^{-1}\), the energy flux through it in the steady state is ........... \(Wm^{-2}\)JEE Mains 2019 Hard
- At what temperature (in \( ^{\circ} C\)) a gold ring of diameter \(6.230\) \(cm\) be heated so that it can be fitted on a wooden bangle of diameter \(6.241 \,cm\) ? Both the diameters have been measured at room temperature \(\left(27^{\circ} C \right)\). (Given: coefficient of linear thermal expansion of gold \(\alpha_{L}=1.4 \times 10^{-5} \,K ^{-1}\) )JEE Mains 2022 Medium
- Two concentric circular coils, \(C _{1}\) and \(C _{2}\), are placed in the \(XY\) plane. \(C _{1}\) has \(500\) turns, and a radius of \(1\; cm . C _{2}\) has \(200\) turns and radius of \(20\, cm . C _{2}\) carries a time dependent current \(I(t)=\left(5 t^{2}-2 t+3\right) \;A\) where \(t\) is in \(s\). The \(emf\) nduced in \(C _{1}\) (in \(mV\) ), at the instant \(t =1\; s\) is \(\frac{4}{ x }\). The value of \(x\) isJEE Mains 2020 Medium
- The atomic mass of \({ }_6 \mathrm{C}^{12}\) is \(12.000000\ \mathrm{u}\) and that of \({ }_6 \mathrm{C}^{13}\) is \(13.003354 \ \mathrm{u}\). The required energy to remove a neutron from \({ }_6 \mathrm{C}^{13}\), if mass of neutron is \(1.008665 \ \mathrm{u}\), will be :JEE Mains 2024 Hard
- What is the dimensional formula of \(a b^{-1}\) in the equation? \(\left(\mathrm{P}+\frac{\mathrm{a}}{\mathrm{V}^2}\right)(\mathrm{V}-\mathrm{b})=\mathrm{RT}\), where letters have their usual meaning.JEE Mains 2024 Hard
- Which level of the single ionized carbon has the same energy as the ground state energy of hydrogen atom ?JEE Mains 2021 Medium
More PYQs from JEE Mains
- In a Young's double slits experiment, the ratio of amplitude of light coming from slits is \(2: 1\). The ratio of the maximum to minimum intensity in the interference pattern is :JEE Mains 2023 Medium
- Four particles each of mass \(1 \mathrm{~kg}\) are placed at four corners of a square of side \(2 \mathrm{~m}\). Moment of inertia of system about an axis perpendicular to its plane and passing through one of its vertex is_________ \(\mathrm{kgm}^2\).
JEE Mains 2024 Hard - A metallic rod of length ' \(L\) ' is rotated with an angular speed of ' \(\omega\) ' normal to a uniform magnetic field ' \(B\) ' about an axis passing through one end of rod as shown in figure. The induced emf will be :
JEE Mains 2023 Medium - In a series \(LCR\) circuit, the inductive reactance \(\left( X _{ L }\right)\) is \(10\, \Omega\) and the capacitive reactance \(\left( X _{ C }\right)\) is \(4\, \Omega\). The resistance \(( R )\) in the circuit is \(6\, \Omega\). The power factor of the circuit is :JEE Mains 2021 Medium