List of top Physics Questions asked in JEE Main

Two thin convex lenses of focal lengths 30 cm and 10 cm are placed coaxially, 10 cm apart. The power of this combination is:
The percentage increase in magnetic field $ B $ when space within a current-carrying solenoid is filled with magnesium (magnetic susceptibility $ \chi_{mg} = 1.2 \times 10^{-5} $) is:
A rod of length $ 5L $ is bent at a right angle, keeping one side length as $ 2L $. The position of the centre of mass of the system (Consider $ L = 10 $ cm):
Two plane polarized light waves combine at a certain point whose electric field components are $ E_1 = E_0 \sin(\omega t) $ $ E_2 = E_0 \sin(\omega t + \frac{\pi}{3}) $ Find the amplitude of the resultant wave.
Two harmonic waves moving in the same direction superimpose to form a wave $ x = a \cos(1.5t) \cos(50.5t) $ where $ t $ is in seconds. Find the period with which they beat (close to the nearest integer):
If $ \epsilon_0 $ denotes the permittivity of free space and $ \Phi_E $ is the flux of the electric field through the area bounded by the closed surface, then the dimension of $ \epsilon_0 \frac{d\Phi_E}{dt} $ are that of:
A solid sphere with uniform density and radius $ R $ is rotating initially with constant angular velocity ($ \omega_1 $) about its diameter. After some time during the rotation, it starts losing mass at a uniform rate, with no change in its shape. The angular velocity of the sphere when its radius becomes $ \frac{R}{2} $ is $ \omega_2 $. The value of $ x $ is ________.

If an optical medium possesses a relative permeability of $ \frac{10}{\pi} $ and relative permittivity of $ \frac{1}{0.0885} $, then the velocity of light is greater in vacuum than in that medium by ________ times. $ (\mu_0 = 4\pi \times 10^{-7} \, \text{H/m}, \quad \epsilon_0 = 8.85 \times 10^{-12} \, \text{F/m}, \quad c = 3 \times 10^8 \, \text{m/s}) $

Displacement of a wave is expressed as $$ x(t) = 5 \cos \left( 628t + \frac{\pi}{2} \right) \, \text{m}. $$ The wavelength of the wave when its velocity is 300 m/s is:

Match List-I with List-II.

A block of mass 25 kg is pulled along a horizontal surface by a force at an angle $ 45^\circ $ with the horizontal. The friction coefficient between the block and the surface is 0.25. The displacement of 5 m of the block is:
For the determination of refractive index of glass slab, a travelling microscope is used whose main scale contains 300 equal divisions equals to 15 cm. The vernier scale attached to the microscope has 25 divisions equals to 24 divisions of main scale. The least count (LC) of the travelling microscope is (in cm):
A wheel is rolling on a plane surface. The speed of a particle on the highest point of the rim is 8 m/s. The speed of the particle on the rim of the wheel at the same level as the center of the wheel, will be:
Consider a n-type semiconductor in which $ n_e $ and $ n_h $ are the number of electrons and holes, respectively.

The displacement $ x $ versus time graph is shown below.
 
The displacement $ x $ is plotted against time $ t $. Choose the correct answer from the options given below:

Three parallel plate capacitors $ C_1 $, $ C_2 $, and $ C_3 $ each of capacitance 5 µF are connected as shown in the figure. The effective capacitance between points A and B, when the space between the parallel plates of $ C_1 $ capacitor is filled with a dielectric medium having dielectric constant of 4, is:

An object is kept at rest at a distance of 3R above the earth’s surface where $ R $ is earth’s radius. The minimum speed with which it must be projected so that it does not return to earth is: (Assume $ M $ = mass of earth, $ G $ = Universal gravitational constant)
There are two vessels filled with an ideal gas where volume of one is double the volume of the other. The large vessel contains the gas at 8 kPa at 1000 K while the smaller vessel contains the gas at 7 kPa at 500 K. If the vessels are connected to each other by a thin tube allowing the gas to flow and the temperature of both vessels is maintained at 600 K, at steady state the pressure in the vessels will be (in kPa).
A cylindrical rod of length 1 m and radius 4 cm is mounted vertically. It is subjected to a shear force of $ 10^5 $ N at the top. Considering infinitesimally small displacement in the upper edge, the angular displacement $ \theta $ of the rod axis from its original position would be: (shear moduli $ G = 10^{10} $ N/m$^2$)

Given below are two statements: 
Statement (I) : The dimensions of Planck’s constant and angular momentum are same. 
Statement (II) : In Bohr’s model, electron revolves around the nucleus in those orbits for which angular momentum is an integral multiple of Planck’s constant. 
In the light of the above statements, choose the most appropriate answer from the options given below:

Consider a rectangular sheet of solid material of length $ \ell = 9 $ cm and width $ d = 4 $ cm. The coefficient of linear expansion is $ \alpha = 3.1 \times 10^{-5} $ K$^{-1}$ at room temperature and one atmospheric pressure. The mass of the sheet is $ m = 0.1 $ kg and the specific heat capacity $ C_v = 900 $ J kg$^{-1}$K$^{-1}$. If the amount of heat supplied to the material is $ 8.1 \times 10^2 $ J, then the change in area of the rectangular sheet is:

A metallic ring is uniformly charged as shown in the figure. AC and BD are two mutually perpendicular diameters. Electric field due to arc AB to O is ‘E’ magnitude. What would be the magnitude of electric field at ‘O’ due to arc ABC?

A radioactive material P first decays into Q and then Q decays to non-radioactive material R. Which of the following figure represents time dependent mass of P, Q and R?
An inductor of self inductance 1 H connected in series with a resistor of 100 $ \Omega $ and an AC supply of 10 V, 50 Hz. Maximum current flowing in the circuit is:
In an electromagnetic system, a quantity defined as the ratio of electric dipole moment and magnetic dipole moment has dimensions of [M$ L^2 T^{-3} A^{-1}]$. The value of P and Q are: