Voltage sensitivity =Vθ=cRNAB Ratio ==( N2 A2 B2N1 A1 B1)R1R2=21×1.8×0.515×3.6×0.25×57=11
JEE Main 2025 — Physics Electromagnetism
In a moving coil galvanometer, two moving coils M1 and M2 have the following particulars :
$\begin{aligned}
& \mathrm{R}_1=5 \Omega, \mathrm{N}_1=15, \mathrm{A}_1=3.6 \times 10^{-3} \mathrm{m}^2, \mathrm{B}_1=0.25 \mathrm{T} \
& \mathrm{R}_2=7 \Omega, \mathrm{N}_2=21, \mathrm{A}_2=1.8 \times 10^{-3} \mathrm{m}^2, \mathrm{B}_2=0.50 \mathrm{T}
\end{aligned}$
Assuming that torsional constant of the springs are same for both coils, what will be the ratio of voltage sensitivity of M1 and M2 ?
Held on 2 Apr 2025 · Verified 6 Jul 2026.
1:1
1:4
1:3
1:2
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.