JEE Main Physics — Electromagnetism previous year questions with solutions.
The electrostatic force $\left(\overrightarrow{F_1}\right)$ and magnetic force $\left(\vec{F}_2\right)$ acting on a charge $q$ moving with velocity $v$ can be written :
The horizontal component of earth's magnetic field at a place is $3.5\times {10}^{-5}T$. A very long straight conductor carrying current of $\sqrt{2}A$ in the direction from South east to North West is placed. The force per unit length experienced by the conductor is ________$\times {10}^{-6}N{m}^{-1}$.
The current of $5A$ flows in a square loop of sides $1m$ is placed in air. The magnetic field at the centre of the loop is $X\sqrt{2}\times {10}^{-7}T$. The value of $X$ is _________.
A charge of $4.0\mu C$ is moving with a velocity of $4.0\times {10}^{6}m{s}^{-1}$ along the positive $y$-axis under a magnetic field $B$ of strength $(2\hat{k})T$. The force acting on the charge is $x\hat{i}N$. The value of $x$ is ______.
Two particles $X$ and $Y$ having equal charges are being accelerated through the same potential difference. Thereafter, they enter normally in a region of uniform magnetic field and describes circular paths of radii ${R}_{1}$ and ${R}_{2}$ respectively. The mass ratio of $X$ and $Y$ is :
The magnetic potential due to a magnetic dipole at a point on its axis situated at a distance of $20\mathrm{cm}$ from its center is $1.5\times {10}^{-5}Tm$. The magnetic moment of the dipole is _______ $A{m}^{2}$. (Given : $\frac{{\mu }_{0}}{4\pi }={10}^{-7}Tm{A}^{-1}$)
An electric field is given by $(6\hat{i}+5\hat{j}+3\hat{k})N{C}^{-1}$. The electric flux through a surface area $30\hat{i}{m}^{2}$ lying in YZ-plane(in SI unit) is:
Two conducting circular loops A and B are placed in the same plane with their centers coinciding as shown in figure. The mutual inductance between them is : 
A coil of $200$ turns and area $0.20{m}^{2}$ is rotated at half a revolution per second and is placed in uniform magnetic field of $0.01T$ perpendicular to axis of rotation of the coil. The maximum voltage generated in the coil is $\frac{2\pi }{\beta }$ volt. The value of $\beta$ is ______.
A horizontal straight wire $5m$ long extending from east to west falling freely at right angle to horizontal component of earth's magnetic field $0.60\times {10}^{-4}\mathrm{Wb}{m}^{-2}$. The instantaneous value of emf induced in the wire when its velocity is $10m{s}^{-1}$ is _______$\times {10}^{-3}V$.
A 2 A current carrying straight metal wire of resistance $1 \Omega$, resistivity $2 \times 10^{-6} \Omega \mathrm{m}$, area of cross-section $10 \mathrm{~mm}^2$ and mass $500 \mathrm{~g}$ is suspended horizontally in mid air by applying a uniform magnetic field $\vec{B}$. The magnitude of $B$ is _____$\times 10^{-1} \mathrm{~T}$ (given, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2$ ).
When a $d c$ voltage of $100 \mathrm{~V}$ is applied to an inductor, a $d c$ current of $5 \mathrm{~A}$ flows through it. When an ac voltage of $200 \mathrm{~V}$ peak value is connected to inductor, its inductive reactance is found to be $20 \sqrt{3} \Omega$. The power dissipated in the circuit is _______ W.
A transformer has an efficiency of $80%$ and works at $10V$ and $4\mathrm{kW}.$ If the secondary voltage is $240V,$ then the current in the secondary coil is:
In series LCR circuit, the capacitance is changed from $C$ to $4C$. To keep the resonance frequency unchanged, the new inductance should be :
Primary coil of a transformer is connected to $220VAC$. Primary and secondary turns of the transforms are $100$ and $10$ respectively. Secondary coil of transformer is connected to two series resistances as shown in figure. The output voltage $({V}_{0})$ is : 
A series LCR circuit with $L=\frac{100}{\pi }\mathrm{mH},C=\frac{{10}^{-3}}{\pi }F$ and $R=10\Omega$, is connected across an AC source of $220V,50\mathrm{Hz}$ supply. The power factor of the circuit would be ____.
For a given series LCR circuit it is found that maximum current is drawn when value of variable capacitance is $25 \mathrm{nF}$. If resistance of $200 \Omega$ and $100 \mathrm{mH}$ inductor is being used in the given circuit. The frequency of ac source is ______ $\times 10^3 \mathrm{~Hz}$. (given $\pi^2=10$ )
A uniform magnetic field of $2\times {10}^{-3}T$ acts along positive Y-direction. A rectangular loop of sides $20\mathrm{cm}$ and $10\mathrm{cm}$ with current of $5A$ is in Y-Z plane. The current is in anticlockwise sense with reference to negative X axis. Magnitude and direction of the torque is :
Given below are two statements : Statement (I) : When currents vary with time, Newton's third law is valid only if momentum carried by the electromagnetic field is taken into account. Statement (II) : Ampere's circuital law does not depend on Biot-Savart's law. In the light of the above statements, choose the correct answer from the options given below :
A capacitor of reactance $4 \sqrt{3} \Omega$ and a resistor of resistance $4 \Omega$ are connected in series with an ac source of peak value $8 \sqrt{2} \mathrm{~V}$. The power dissipation in the circuit is ________ W.
A LCR circuit is at resonance for a capacitor $C$, inductance $L$ and resistance $R$. Now the value of resistance is halved keeping all other parameters same. The current amplitude at resonance will be now:
An alternating voltage $V(t)=220\mathrm{sin}100\pi t$ volt is applied to a purely resistive load of $50\Omega$. The time taken for the current to rise from half of the peak value to the peak value is:
Match List-I with List-II : $\begin{array}{|c|c|c|c|} \hline & \text { List-I } & & \text { List-II } \\ \hline & \text { EM-Wave } & & \text { Wavelength Range } \\ \hline \text { (A) } & \text { Infra-red } & \text { (I) } & < 10^{-3} \mathrm{~nm} \\ \hline \text { (B) } & \text { Ultraviolet } & \text { (II) } & 400 \mathrm{~nm} \text { to } 1 \mathrm{~nm} \\ \hline \text { (C) } & \text { X-rays } S & \text { (III) } & 1 \mathrm{~mm} \text { to } 700 \mathrm{~nm} \\ \hline \text { (D) } & \text { Gamma rays } & \text { (IV) } & 1 \mathrm{~nm} \text { to } 10^{-3} \mathrm{~nm} \\ \hline \end{array}$
Match List-I with List-II :   Choose the correct answer from the options given below :