JEE Main Physics — Electromagnetism previous year questions with solutions.
Two short magnetic dipoles ${m}_{1}$ and ${m}_{2}$ each having magnetic moment of $1A{m}^{2}$ are placed at point $O$ and $P$ respectively. The distance between $OP$ is $1m$. The torque experienced by the magnetic dipole ${m}_{2}$ due to the presence of ${m}_{1}$ is $________\times {10}^{-7}Nm$ 
Intensity of sunlight is observed as $0.092{\mathrm{Wm}}^{-2}$ at a point in free space. What will be the peak value of magnetic field at that point ? $({\epsilon }_{0}=8.85\times {10}^{-12}{C}^{2}{N}^{-1}{m}^{-2})$
An electron with kinetic energy ${K}_{1}$ enters between parallel plates of a capacitor at an angle $\alpha$ with the plates. It leaves the plates at angle $\beta$ with kinetic energy ${K}_{2}.$ Then the ratio of kinetic energies ${K}_{1}:{K}_{2}$ will be :
The peak electric field produced by the radiation coming from the $8W$ bulb at a distance of $10m$ is $\frac{x}{10}\sqrt{\frac{{\mu }_{0}c}{\pi }}V{m}^{-1}$. The efficiency of the bulb is $10%$ and it is a point source. The value of $x$ is,
What will be the magnitude of the electric field at point $O$ as shown in the figure? Each side of the figure is $l$ and perpendicular to the other? 
In an $LCR$ series circuit, an inductor $30\mathrm{mH}$ and a resistor $1\Omega$ are connected to an $\mathrm{AC}$ source of angular frequency $300\mathrm{rad}{s}^{-1}.$ The value of capacitance for which the current leads the voltage by $45^{\circ}$ is $\frac{1}{x}\times {10}^{-3}F$. Then the value of $x$ is
In an electromagnetic wave, the electric field vector and magnetic field vector are given as $\vec{E}={E}_{0}\hat{i}$ and $\vec{B}={B}_{0}\hat{k}$, respectively. The direction of propagation of electromagnetic wave is along:
A coil in the shape of an equilateral triangle of side $10\mathrm{cm}$ lies in a vertical plane between the pole pieces of permanent magnet producing a horizontal magnetic field $20\mathrm{mT}$. The torque acting on the coil when a current of $0.2A$ is passed through it and its plane becomes parallel to the magnetic field will be $\sqrt{x}\times {10}^{-5}\mathrm{Nm}$. The value of $x$ is
For changing the capacitance of a given paralle plate capacitor, a dielectric material of dielectric constant $K$ is used, which has the same area as the plates of the capacitor. The thickness of the dielectric slab is $\frac{3}{4}d$, where $d$ is the separation between the plates of parallel plate capacitor. The new capacitance ${C}^{'}$ in terms of original capacitance ${C}_{0}$ is given by the following relation :
The resistance of a conductor at $15^{\circ}C$ is $16\Omega$ and at $100^{\circ}C$ is $20\Omega .$ What will be the temperature coefficient of resistance of the conductor?
A current of $1.5A$ is flowing through a triangle, of side $9\mathrm{cm}$ each. The magnetic field at the centroid of the triangle is : (Assume that the current is flowing in the clockwise direction.)
A current of $6A$ enters one corner $P$ of an equilateral triangle $PQR$ having $3$ wires of resistance $2\Omega$ each and leaves by the corner $R.$ The currents ${i}_{1}$ in ampere is 
Two electrons each are fixed at a distance $2d.$ A third charge proton placed at the midpoint is displaced slightly by a distance $x(x\ll d)$ perpendicular to the line joining the two fixed charges. Proton will execute simple harmonic motion having angular frequency: ($m=$ mass of charged particle)
Match List I with List II. <table class="pyq-table"><tbody><tr><td></td><td>List I</td><td></td><td>List II</td></tr><tr><td>(a)</td><td>Rectifier</td><td>(i)</td><td>Used either for stepping up or stepping down the A.C. voltage</td></tr><tr><td>(b)</td><td>Stabilizer</td><td>(ii)</td><td>Used to convert A.C. voltage into D.C. voltage</td></tr><tr><td>(c)</td><td>Transformer</td><td>(iii)</td><td>Used to remove any ripple in the rectified output voltage</td></tr><tr><td>(d)</td><td>Filter</td><td>(iv)</td><td>Used for constant output voltage even when the input voltage or load current change</td></tr></tbody></table>Choose the correct answer from the options given below:
Four identical long solenoids $A,B,C$ and $D$ are connected to each other as shown in the figure. If the magnetic field at the center of $A$ is $3T$ the field at the center of $C$ would be : (Assume that the magnetic field is confined with in the volume of respective solenoid). 
A resistor dissipates $192J$ of energy in $1s$ when a current of $4A$ is passed through it. Now, when the current is doubled, the amount of thermal energy dissipated in $5s$ is _____________ $J.$
The voltage across the $10\Omega$ resistor in the given circuit is $x$ volt.  The value of $x$ to the nearest integer is _____.
Find the electric field at point $P$ (as shown in figure) on the perpendicular bisector of a uniformly charged thin wire of length $L$ carrying a charge $Q$. The distance of the point $P$ from the centre of the rod is $a=\frac{\sqrt{3}}{2}L$ 
A parallel plate capacitor with plate area '$A$' and distance of separation '$d$' is filled with a dielectric. What is the capacity of the capacitor when permittivity of the dielectric varies as: $\epsilon (x)={\epsilon }_{0}+kx$, for $(0<x\leq \frac{d}{2})$ $\epsilon (x)={\epsilon }_{0}+k(d-x)$, for $(\frac{d}{2}\leq x\leq d)$
A constant magnetic field of $1T$ is applied in the $x>0$ region. A metallic circular ring of radius $1m$ is moving with a constant velocity of $1m{s}^{-1}$ along the $x$-axis. At $t=0s$, the centre $O$ of the ring is at $x=-1m$. What will be the value of the induced emf in the ring at $t=1s$ ? (Assume the velocity of the ring does not change.) 
A $10\Omega$ resistance is connected across $220V-50\mathrm{Hz}$ AC supply. The time taken by the current to change from its maximum value to the $\mathrm{rms}$ value is:
The equivalent resistance of the given circuit between the terminals $A$ and $B$ is : 
A coaxial cable consists of an inner wire of radius $a$ surrounded by an outer shell of inner and outer radii $b$ and $c$ respectively. The inner wire carries an electric current ${i}_{0}$ which is distributed uniformly across cross-sectional area. The outer shell carries an equal current in opposite direction and distributed uniformly. What will be the ratio of the magnetic field at a distance $x$ from the axis when $(i)$ $x<a$ and $(ii)$ $a<x<b$ ?
A cell ${E}_{1}$ of emf $6V$ and internal resistance $2\Omega$ is connected with another cell ${E}_{2}$ of emf $4V$ and internal resistance $8\Omega$ (as shown in the figure). The potential difference across points $X$ and $Y$ is: 