Given: θ=0.05rad,I=10mA,K=4×10−5Nmrad−1,B=0.01T,N=200
The torsional constant of a wire used in a moving coil galvanometer is given by
K=θNIAB, where, A is area of each turn
So, A=NIBKθ=200×10×10−3×0.014×10−5×0.05
Thus, A=10−4m2=1cm2
JEE Main 2023 — Physics Electromagnetism
For a moving coil galvanometer, the deflection in the coil is 0.05rad when a current of 10mA is passed through it. If the torsional constant of suspension wire is 4.0×10–5Nmrad−1, the magnetic field is 0.01T and the number of turns in the coil is 200, the area of each turn (in cm2 ) is :
Held on 25 Jan 2023 · Verified 6 Jul 2026.
2.0
1.0
1.5
0.5
Sign in to track your attempts and accuracy.
Sign in to keep a private note on this question. Nothing you write is ever public.
A square loop of side $2$ cm is placed in a time varying magnetic field with magnitude as $B = 0.4\sin(300t)$ Tesla. The normal to the plane of loop makes an angle of $60°$ with the field. The maximum induced emf produced in the loop is __________ mV.
A circular coil of radius $2$ cm and $125$ turns carries a current of $1$ A. The coil is placed in a uniform magnetic field of magnitude $0.4$ T. The axis of the coil makes an angle of $30°$ with the direction of the magnetic field. The torque acting on the coil is $\alpha \times 10^{-4}$ N.m. The value of $\alpha$ is ______. ($\pi=3.14$)
$1\,\mu$C charge moving with velocity $\vec{v} = \left(\hat{i} - 2\hat{j} + 3\hat{k}\right)$ m/s in the region of magnetic field $\vec{B} = \left(2\hat{i} + 3\hat{j} - 5\hat{k}\right)$ T. The magnitude of force acting on it is $\sqrt{\alpha} \times 10^{-6}$ N. The value of $\alpha$ is _______.
A charged particle moves in a uniform magnetic field. If the velocity is perpendicular to the field, the path of the particle is:
Three identical coils $C_{1}, C_{2}$ and $C_{3}$ are closely placed such that they share a common axis. $C_{2}$ is exactly midway. $C_{1}$ carries current $I$ in anti-clockwise direction while $C_{3}$ carries current $I$ in clockwise direction. An induced current flows through $C_{2}$ will be in clockwise direction when
Work through every JEE Main Electromagnetism PYQ, year by year.