JEE Mains · Physics · STD 12 - Moving charges and magnetism
- JEE Mains 2023
- Medium
- MCQ
The magnetic moments associated with two closely wound circular coils \(A\) and \(B\) of radius \(r_A=10 cm\) and \(r_B=20 cm\) respectively are equal if: (Where \(N _A, I _{ A }\) and \(N _B, I _{ B }\) are number of turn and current of \(A\) and \(B\) respectively)
Pick an option to check your answer.
Answer & Solution
Correct Answer
(C) \(N _{ A } I _{ A }=4 N _{ B } I _{ B }\)
Step-by-step Solution
Detailed explanation
\(M = NIA\)
\(M _{ A }= M _{ B }\)
\(N _{ A } I _{ A } A _{ A }= N _{ B } I _{ B } A _{ B }\)
\(N _{ A } I _{ A } \pi(0.1)^2= N _{ B } I _{ B } \pi(0.2)^2\)
\(N _{ A } I _{ A }=4 N _{ B } I _{ B }\)
More questions from Physics
- In a resonance tube experiment when the tube is filled with water up to height of \(17.0\, cm\) from bottom, it resonates with a given tuning fork. When the water level is raised the next resonance with the same tuning fork occurs at a height of \(24.5\, cm\). If the velocity of sound in air is \(330\, m / s ,\) the tuning fork frequency is\(......Hz\)JEE Mains 2020 Hard
- The position of an object having mass \(0.1\) kg as a function of time \(t\) is given as \(\vec{r} = \left(10t^2\hat{i} + 5t^3\hat{j}\right)\) m. At \(t = 1\) s, which of the following statements are correct?
A. The linear momentum \(\vec{p} = \left(2\hat{i} + 1.5\hat{j}\right)\) kg·m/s.
B. The force acting on the object \(\vec{F} = \left(2\hat{i} + 3\hat{j}\right)\) N.
C. The angular momentum of the object about its origin \(\vec{L} = 15\hat{k}\) J·s.
D. The torque acting on the object about its origin \(\vec{\tau} = 20\hat{k}\) N·m.
Choose the correct answer from the options given below :JEE Mains 2026 Medium - For the given figures, choose the correct options:
JEE Mains 2023 Medium - Identify the logic operation performed by the given circuit.
JEE Mains 2024 Hard - The ranges and heights for two projectiles projected with the same initial velocity at angles \(42^{\circ}\) and \(48^{\circ}\) with the horizontal are \({R}_{1}, {R}_{2}\) and \({H}_{1}\), \({H}_{2}\) respectively. Choose the correct option:JEE Mains 2021 Medium
- An infinite number of point charges, each carrying \(1 \,\mu C\) charge, are placed along the y-axis at \(y=1\, m , 2\, m , 4 \,m , 8\, m \ldots \ldots \ldots \ldots \ldots\) The total force on a \(1 \,C\) point charge, placed at the origin, is \(x \times 10^{3}\, N\). The value of \(x\), to the nearest integer, is ......... [Take \(\left.\frac{1}{4 \pi \epsilon_{0}}=9 \times 10^{9} \,Nm ^{2} / C ^{2}\right]\)JEE Mains 2021 Medium
More PYQs from JEE Mains
- Assuming the earth to be a sphere of uniform mass density, the weight of a body at a depth \(d=\frac{R}{2}\) from the surface of earth, if its werght on the surface of earth is \(200\,N\), will be \(...........\,N\) ( \(Given R =\) Radrus of earth)JEE Mains 2023 Medium
- The recoil speed of a hydrogen atom after it emits a photon in going from \(n =5\) state to \(n =1\) state will be ..... \(m/s\)JEE Mains 2021 Hard
- The vehicles carrying inflammable fluids usually have _______ metallic chains touching the ground.JEE Mains 2024 Hard
- If the Earth has no rotational motion, the weight of a person on the equator is \(W\). Determine the speed with which the earth would have to rotate about its axis so that the person at the equator will weight \(\frac{3}{4}\,W\) . Radius of the Earth is \(6400\, km\) and \(g = 10\, m/s^2\)JEE Mains 2017 Medium
- In a metre-bridge when a resistance in the left gap is \(2\ \Omega\) and unknown resistance in the right gap, the balance length is found to be \(40\ \mathrm{cm}\). On shunting the unknown resistance with \(2\ \Omega\), the balance length changes by _______.JEE Mains 2024 Hard