List of top Physics Questions asked in JEE Main

A slab is subjected to two forces \(\vec{F_1}\) and \(\vec{F_2}\) of same magnitude \(F\) as shown in the figure. Force \(\vec{F_2}\) is in XY-plane while force \(\vec{F_1}\) acts along z-axis at the point \((2\hat{i} + 3\hat{j})\). The moment of these forces about point O will be :
A particle is moving along a circular path with a constant speed of \(10\ \mathrm{ms^{-1}}\). What is the magnitude of the change in velocity of the particle, when it moves through an angle of \(60^\circ\) around the centre of the circle?
Three charges \(Q\), \(+q\) and \(+q\) are placed at the vertices of a right-angle isosceles triangle as shown below. The net electrostatic energy of the configuration is zero, if the value of \(Q\) is :
The given graph shows variation (with distance \(r\) form centre) of :
An equilateral triangle ABC is cut from a thin solid sheet of wood. (see figure) D, E and F are the mid-points of its sides as shown and G is the centre of the triangle. The moment of inertia of the triangle about an axis passing through G and perpendicular to the plane of the triangle is \(I_0\). If the smaller triangle DEF is removed from ABC, the moment of inertia of the remaining figure about the same axis is I. then :
In a Wheatstone bridge (see fig.), Resistances \(P\) and \(Q\) are approximately equal. When \(R = 400\ \Omega\), the bridge is balanced. On interchanging \(P\) and \(Q\), the value of \(R\), for balance, is \(405\ \Omega\). The value of \(X\) is close to :
The modulation frequency of an AM radio station is 250 kHz, which is 10% of the carrier wave. If another AM station approaches you for license what broadcast frequency will you allot ?
An unknown metal of mass 192 g heated to a temperature of \(100^\circ\mathrm{C}\) was immersed into a brass calorimeter of mass 128 g containing 240 g of water at a temperature of \(8.4^\circ\mathrm{C}\). Calculate the specific heat of the unknown metal if water temperature stabilizes at \(21.5^\circ\mathrm{C}\). (Specific heat of brass is 394 J kg-1 K-1)
A parallel plate capacitor having capacitance 12 pF is charged by a battery to a potential difference of 10 V between its plates. The charging battery is now disconnected and a porcelain slab of dielectric constant 6.5 is slipped between the plates. The work done by the capacitor on the slab is :
A hoop and a solid cylinder of same mass and radius are made of a permanent magnetic material with their magnetic moment parallel to their respective axes. But the magnetic moment of hoop is twice of solid cylinder. They are placed in a uniform magnetic field in such a manner that their magnetic moments make a small angle with the field. If the oscillation periods of hoop and cylinder are Th and Tc respectively, then -
Two kg of a monoatomic gas is at a pressure of \(4\times10^4\ \mathrm{N/m^2}\). The density of the gas is 8 kg/m3. What is the order of energy of the gas due to its thermal motion ?
A metal plate of area \(1\times10^{-4}\ \mathrm{m^2}\) is illuminated by a radiation of intensity 16 mW/m2. The work function of the metal is 5 eV. The energy of the incident photons is 10 eV and only 10% of it produces photo electrons. The number of emitted photoelectrons per second and their maximum energy, respectively, will be
A current of 2 mA was passed through an unknown resistor which dissipated a power of 4.4 W. Dissipated power when an ideal power supply of 11 V is connected across it is -
Four equal point charges Q each are placed in the xy plane at (0, 2), (4, 2), (4, -2) and (0, -2). The work required to put a fifth charge Q at the origin of the coordinate system will be -
Charges -q and +q located at A and B, respectively, constitute an electric dipole. Distance AB = 2a, O is the mid point of the dipole and OP is perpendicular to AB. A charge Q is placed at P where OP = y and y >> 2a. The charge Q experiences an electrostatic force F. If Q is now moved along the equatorial line to P' such that OP' = \(\left(\frac y3\right)\), the force on Q will be close to - \(\left(\frac y3\gg2a\right)\)
A particle starts from the origin at time t = 0 and moves along the positive x-axis. The graph of velocity with respect to time is shown in figure. What is the position of the particle at time t = 5s ?
The electric field of a plane polarized electromagnetic wave in free space at time t = 0 is given by an expression
\(\vec E(x,y)=10\hat j\cos[(6x+8z)]\).
The magnetic field \(\vec B(x,z,t)\) is given by - (c is the velocity of light)
The diameter and height of a cylinder are measured by a meter scale to be \(12.6\pm0.1\) cm and \(34.2\pm0.1\) cm, respectively. What will be the value of its volume in appropriate significant figures ?
A particle which is experiencing a force, given by
\(\vec F=3\hat i-12\hat j\),
undergoes a displacement of
\(\vec d=4\vec i\)
particle had a kinetic energy of 3 J at the beginning of the displacement, what is its kinetic energy at the end of the displacement ?
Consider a Young's double slit experiment as shown in figure. What should be the slit separation d in terms of wavelength \(\lambda\) such that the first minima occurs directly in front of the slit (S1) ?
A TV transmission tower has a height of 140 m and the height of the receiving antenna is 40 m. What is the maximum distance upto which signals can be broadcasted from this tower is LOS (Line of Sight) mode ? (Given : radius of earth = \(6.4 \times 10^{6}\) m).
A train moves towards a stationary observer with speed 34 m/s. The train sounds a whistle and its frequency registered by the observer is \(f_1\). If the speed of the train is reduced to 17 m/s, the frequency registered is \(f_2\). If speed of sound is 340 m/s, then the ratio \(f_1/f_2\) is -
Using a nuclear counter the count rate of emitted particles from a radioactive source is measured. At t = 0 it was 1600 counts per second and t = 8 seconds it was 100 counts per second. The count rate observed, as counts per second, at t = 6 seconds is close to -
A block of mass m is kept on a platform which starts from rest with constant acceleration g/2 upward, as shown in figure. Work done by normal reaction on block in time \(t\) is -
A satellite is moving with a constant speed v in circular orbit around the earth. An object of mass 'm' is ejected from the satellite such that it just escapes from the gravitational pull of the earth. At the time of ejection, the kinetic energy of the object is -