List of top Physics Questions asked in JEE Main

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)
Two identical bodies, projected with the same speed at two different angles cover the same horizontal range \(R\). If the time of flight of these bodies are 5 s and 10 s, respectively, then the value of \(R\) is ________ m. (Take \(g = 10\) m/s²)
A thin biconvex lens is prepared from the glass (\(\mu = 1.5\)) both curved surfaces of which have equal radii of 20 cm each. Left side surface of the lens is silvered from outside to make it reflecting. To have the position of image and object at the same place, the object should be placed from the lens at a distance of ________ cm.
A gas balloon is going up with a constant velocity of 10 m/s. When this balloon reached a height of 75 m, a stone is dropped from it and balloon keeps moving up with the same velocity. The height of the balloon when the stone hits the ground is ________ m. (Take \(g = 10\) m/s²)
A car moving with a speed of 54 km/h takes a turn of radius 20 m. A simple pendulum is suspended from the ceiling of the car. Determine the angle made by the string of the pendulum with the vertical during the turning. (Take \(g = 10\) m/s²)
Consider the equation \(H = \frac{x^p \varepsilon^q E^r}{t^s}\), where \(H\) = magnetic field, \(E\) = electric field, \(\varepsilon\) = permittivity, \(x\) = distance, \(t\) = time. The values of \(p, q, r\) and \(s\) respectively are:
A new unit (\(\alpha\)) of length is chosen such that it is equal to the speed of light in vacuum. What is the distance between Venus and Earth in terms of \(\alpha\) units if light takes 6 min. 40 s to cover this distance?
A thin half ring of radius $35 \text{ cm}$ is uniformly charged with a total charge of $Q$ coulomb. If the magnitude of the electric field at centre of the half ring is $100 \text{ V/m}$, then the value of $Q$ is ______ $\text{nC}$.
($\epsilon_o = 8.85 \times 10^{-12} \text{ C}^2/\text{Nm}^2$ and $\pi = 3.14$)

An object of uniform density rolls up the curved path with the initial velocity $v_o$ as shown in the figure. If the maximum height attained by an object is $\frac{7v_o^2}{10 g}$ ($g=$ acceleration due to gravity), the object is a _______

A body of mass $m$ is taken from the surface of earth to a height equal to twice the radius of earth ($R_e$). The increase in potential energy will be ____ ($g$ is acceleration due to gravity at the surface of earth)

Eight mercury drops, each of radius $r$, coalesce to form a bigger drop. The surface energy released in this process is _____ ($S$ is the surface tension of mercury).

An ideal gas at pressure $P$ and temperature $T$ is expanding such that $PT^3 =$ constant. The coefficient of volume expansion of the gas is ____

Under steady state condition the potential difference across the capacitor in the circuit is _____ V. 
 

An object AB is placed 15 cm on the left of a convex lens P of focal length 10 cm. Another convex lens Q is now placed 15 cm right of lens P. If the focal length of lens Q is 15 cm, the final image is _____

A copper wire of length 3 m is stretched by 3 mm by applying an external force. The volume of the wire is \( 600 \times 10^{-6} \text{ m}^3 \). The elastic potential energy stored in the wire in stretched condition would be _____J. (Given Young's modulus of copper = \( 1.1 \times 10^{11} \text{ N/m}^2 \))}