List of top Physics Questions asked in JEE Main

Four particles A, B, C and D with masses \(m_A = m\), \(m_B = 2m\), \(m_C = 3m\) and \(m_D = 4m\) are at the corners of a square. They have accelerations of equal magnitude with directions as shown. The acceleration of the centre of mass of the particles is :
To double the covering range of a TV transmission tower, its height should be multiplied by :
A paramagnetic material has \(10^{28}\) atoms/m\(^3\). Its magnetic susceptibility at temperature 350 K is \(2.8 \times 10^{-4}\). Its susceptibility at 300 K is :
In a Frank-Hertz experiment, an electron of energy 5.6 eV passes through mercury vapour and emerges with an energy 0.7 eV. The minimum wavelength of photons emitted by mercury atoms is close to :
Formation of real image using a biconvex lens is shown below :

If the whole set up is immersed in water without disturbing the object and the screen positions, what will one observe on the screen ?
A particle of mass 20 g is released with an initial velocity 5 m/s along the curve from the point A, as shown in the figure. The point A is at height h from point B. The particle slides along the frictionless surface. When the particle reaches point B, its angular momentum about O will be :
(Take g = 10 m/s2)
Let \(\ell\), r, C and V represent inductance, resistance, capacitance and voltage, respectively. The dimension of \(\frac{\ell}{rCV}\) in SI units will be :
Two satellites, A and B, have masses m and 2m respectively. A is in a circular orbit of radius R, and B is in a circular orbit of radius 2R around the earth. The ratio of their kinetic energies, \(T_A/T_B\), is ;
The mean intensity of radiation on the surface of the Sun is about \(10^8\) W/m2. The rms value of the corresponding magnetic field is closet to :
When a certain photosensitive surface is illuminated with monochromatic light of frequency v, the stopping potential for the current is \(-V_0/2\). When the surface is illuminated by monochromatic light of frequency v/2, the stopping potential is \(-V_0\). The threshold frequency for photoelectric emission is :
The charge on a capacitor plate in a circuit, as a function of time, is shown in the figure :

What is the value of current at t = 4 s ?
Two particles A, B are moving on two concentric circles of radii \(R_1\) and \(R_2\) with equal angular speed \(\omega\). At t = 0, their positions and direction of motion are shown in the figure.

The relative velocity \(\vec V_A-\vec V_B\) at \(t=\frac{\pi}{2\omega}\) is given by :
In the above circuit, \(C=\frac{\sqrt3}{2}\,\mu\mathrm{F}\), \(R_2=20\,\Omega\), \(L=\frac{\sqrt3}{10}\) H and \(R_1=10\,\Omega\). Current in L-\(R_1\) path is \(I_1\) and in C-\(R_2\) path it is \(I_2\). The voltage of A.C. source is given by, \(V=200\sqrt2\sin(100t)\) volts. The phase difference between \(I_1\) and \(I_2\) is :
A parallel plate capacitor with plates of area 1 m2 each, are at a separation of 0.1 m. If the electric field between the plates is 100 N/C, the magnitude of charge on each plate is :
(Take \(\varepsilon_0=8.85\times10^{-12}\ \frac{\mathrm{C^2}}{\mathrm{N\,m^2}}\))
A simple harmonic motion is represented by :
\(y=5(\sin3\pi t+\sqrt3\cos3\pi t)\) cm
The amplitude and time period of the motion are :
A 100 V carrier wave is made to vary between 160 V and 40 V by a modulating signal. What is the modulation index ?
A cylinder of radius R is surrounded by a cylindrical shell of inner radius R and outer radius 2R. The thermal conductivity of the material of the inner cylinder is \(K_1\) and the of the outer cylinder is \(K_2\). Assuming no loss of heat, the effective thermal conductivity of the system for heat flowing along the length of the cylinder is :
As shown in the figure, two infinitely long, identical wires are bent by \(90^\circ\) and placed in such a way that the segments LP and QM are along the x-axis, while segments PS and QN are parallel to the y-axis. If OP = OQ = 4 cm, and the magnitude of the magnetic field at O is \(10^{-4}\) T, and the two wires carry equal currents (see figure), the magnitude of the current in each wire and the direction of the magnetic field at O will be (\(\mu_0 = 4\pi \times 10^{-7}\ \mathrm{NA^{-2}}\)) :
A light wave is incident normally on a glass slab of refractive index 1.5. If 4 % of light gets reflected and the amplitude of the electric field of the incident light is 30 V/m, then the amplitude of the electric field for the wave propagating in the glass medium will be :
Two electric bulbs, rated at (25 W, 220 V) and (100 W, 220 V), are connected in series across a 220 V voltage source. If the 25 W and 100 W bulbs draw powers \(P_1\) and \(P_2\) respectively, then :
A particle A of mass 'm' and charge 'q' is accelerated by a potential difference of 50 V. Another particle B of mass '4 m' and charge 'q' is accelerated by a potential difference of 2500 V. The ratio of de-Broglie wavelengths \(\dfrac{\lambda_A}{\lambda_B}\) is close to :
In the figure shown, a circuit contains two identical resistors with resistance \(R = 5\,\Omega\) and an inductance with \(L = 2\,\text{mH}\). An ideal battery of 15 V is connected in the circuit. What will be the current through the battery long after the switch is closed ?
Two light identical springs of spring constant k are attached horizontally at the two ends of a uniform horizontal rod AB of length \(\ell\) and mass m. The rod is pivoted at its centre 'O' and can rotate freely in horizontal plane. The other ends of the two springs are fixed to rigid supports as shown in figure. The rod is gently pushed through a small angle and released. The frequency of resulting oscillation is :
The position vector of the centre of mass \(\vec{r}_{cm}\) of an asymmetric uniform bar of negligible area of crosssection as shown in figure is :
A point source of light, S is placed at distance L in front of the centre of plane mirror of width d which is hanging vertically on a wall. A man walks in front of the mirror along a line parallel to the mirror, at a distance 2L as shown below. The distance over which the man can see the image of the light source in the mirror is