List of top Physics Questions asked in JEE Main

A new unit (\(\alpha\)) of length is chosen such that it is equal to the distance travelled by light in vacuum in 1 second. What is the distance between Venus and Earth in terms of this new unit. If light takes 6 min 40 sec to cover the distance.

A solid cylinder of mass \(m\) and radius \(R\) is projected on a rough surface having kinetic friction coefficient \( \mu_k \) with velocity \(v_0\) and angular velocity \( \omega_0 \) as shown in the figure. Find out time after which rolling starts. \((\omega_0 = \frac{v_0}{4R})\)

A biconvex lens having radius of curvature \(20\,\text{cm}\) for both surfaces and one side of the lens is silvered as shown in the figure. Object is at distance \(x\) cm from the lens. Find \(x\) such that image is on the object itself. Given \( \mu = 1.5 \).

For the logic gate shown in the diagram, find the output \(Y\) for the given inputs \(A\) and \(B\).

Two masses of 3.4 kg and 2.5 kg are accelerated from an initial speed of 5 m/s and 12 m/s, respectively. The distances traversed by the masses in the 5th second are 104 m and 129 m, respectively. The ratio of their momenta after 10 s is \(\frac{x}{8}\). The value of \(x\) is ________.

The stored charge in the capacitor in steady state of the following circuit is ________ µC.

A 5 mg particle carrying a charge of \(5\pi \times 10^{-6}\) C is moving with velocity of \((3\hat{i} + 2\hat{k}) \times 10^{-2}\) m/s in a region having magnetic field \(\vec{B} = 0.1 \hat{k}\) Wb/m². It moves a distance of \(a\) meter along \(\hat{k}\) when it completes 5 revolutions. The value of \(a\) is ________.

Some distant star is to be observed by some telescope of diameter of objective lens \(a\), at an angular resolution of \(3.0 \times 10^{-7}\) radian. If the wavelength of light from the star reaching the telescope is 500 nm, the minimum diameter of the objective lens of the telescope is ________ cm.

A parallel plate capacitor has a separation between plates of 0.885 mm. It has a capacitance of $1\,\mu\text{F}$ when the space between the plates is filled with an insulating material of resistivity $1 \times 10^{13}\,\Omega\,\text{m}$ and resistance $17.7 \times 10^{14}\,\Omega$. The relative permittivity of the insulating material is $\alpha \times 10^7$. The value of $\alpha$ is \underline{\hspace{2cm}}.

The output Y for the given inputs A and B to the circuit is:}

Two radioactive substances A and B of mass numbers 200 and 212 respectively, shows spontaneous \(\alpha\)-decay with same Q value of 1 MeV. The ratio of energies of \(\alpha\)-rays produced by A and B is ________.

\(K_1\) and \(K_2\) be the maximum kinetic energies of photoelectrons emitted from a surface of a given material for the light of wavelength \(\lambda_1\) and \(\lambda_2\), respectively. If \(\lambda_1 = 2\lambda_2\) then the work function of material is given by:

Light ray incident along a vector \(\vec{AO}\) (\(AO = 2\hat{i} - 3\hat{j}\)) emerges out along vector \(\vec{OB}\) (\(OB = C\hat{i} - 4\hat{j}\)) as shown in the figure below. The value of \(C\) is ________.

Two point charges \(q_1 = 3\) $\mu$C and \(q_2 = -4\) $\mu$C are placed at points \((2\hat{i} + 3\hat{j} + 3\hat{k})\) and \((\hat{i} + \hat{j} + \hat{k})\) respectively. Force on charge \(q_2\) is \underline{\hspace{2cm}} N. (Take \(\frac{1}{4\pi\epsilon_0} = 9 \times 10^9\) SI Units)

A 30 cm long solenoid has 10 turns per cm and area of 5 cm². The current through the solenoid coil varies from 2 A to 4 A in 3.14 s. The e.m.f. induced in the coil is \(\alpha \times 10^{-5}\) V. The value \(\alpha\) is ________.

A current carrying circular loop of radius 2 cm with unit normal \(\hat{n} = \frac{\hat{k} + \hat{i}}{\sqrt{2}}\) is placed in a magnetic field, \(\vec{B} = B_0 (3\hat{i} + 2\hat{k})\). If \(B_0 = 4 \times 10^{-3}\) T and current \(I = 100\sqrt{2}\) A, the torque experienced by the loop is ________ Wb·A.

A monochromatic source of light operating at 15 kW emits \(2.5 \times 10^{22}\) photons/s. The region of an electromagnetic spectrum to which the emitted electromagnetic radiation belongs to ________.

The frequency of oscillation of a mass \(m\) suspended by a spring is \(v_1\). If the length of the spring is cut to half, the same mass oscillates with frequency \(v_2\). The value of \(\frac{v_2}{v_1}\) is ________.

Initial pressure and volume of a monoatomic ideal gas are \(P\) and \(V\). The change in internal energy of this gas in adiabatic expansion to volume \(V_{\text{final}} = 8V\) is ________ J.

One mole of diatomic gas having rotational modes only is kept in a cylinder with a piston system. The cross-section area of the cylinder is 4 cm². The gas is heated slowly to raise the temperature by 1.2 °C during which the piston moves by 25 mm. The amount of heat supplied to the gas is ________ J. (Atmospheric pressure = 100 kPa, \(R = 8.3\) J/mol·K) (Neglect mass of the piston)

A spherical liquid drop of radius \(R\) acquires the terminal velocity \(v_1\) when falls through a gas of viscosity \(\eta\). Now the drop is broken into 64 identical droplets and each droplet acquires terminal velocity \(v_2\) falling through the same gas. The ratio of terminal velocities \(v_1/v_2\) is ________.

A liquid of density 600 kg/m³ flowing steadily in a tube of varying cross-section. The cross-section at a point A is 1.0 cm² and that at B is 20 mm². Both the points A and B are in same horizontal plane, the speed of the liquid at A is 10 cm/s. The difference in pressures at A and B points is ________ Pa.

A solid cylinder having radius \(R\) and length \(L\) is slipping on a rough horizontal plane. At time \(t = 0\) the cylinder has a translational velocity \(v_0 = 49\) m/s, perpendicular to its axis and a rotational velocity \(v_0/4R\) about the centre. The time taken by the cylinder to start rolling is ________ seconds. (coefficient of kinetic friction \(\mu_k = 0.25\) and \(g = 9.8\) m/s²)