List of top Physics Questions asked in JEE Main

If the time period of a two meter long simple pendulum is 2 s, the acceleration due to gravity at the place where pendulum is executing S.H.M. is :

In the given figure, a mass M is attached to a horizontal spring which is fixed on one side to a rigid support. The spring constant of the spring is k. The mass oscillates on a frictionless surface with time period T and amplitude A. When the mass is in equilibrium position, another mass m is gently fixed upon it. The new amplitude of oscillation will be : 

The function of time representing a simple harmonic motion with a period of \(\frac{\pi}{\omega}\) is:

In the reported figure, two bodies A and B of masses 200 g and 800 g are attached with the system of springs. Springs are kept in a stretched position with some extension when the system is released. The horizontal surface is assumed to be frictionless. The angular frequency will be ________ rad/s when $k = 20 \text{ N/m}$. 

A particle performs simple harmonic motion with a period of 2 second. The time taken by the particle to cover a displacement equal to half of its amplitude from the mean position is 1/a s. The value of 'a' to the nearest integer is __________.

In the given figure, a body of mass M is held between two massless springs, on a smooth inclined plane. If each spring has spring constant k, the frequency of oscillation of given body is : 

When a particle executes SHM, the nature of graphical representation of velocity as a function of displacement is :
A uniform chain of length 3 meter and mass 3 kg overhangs a smooth table with 2 meter laying on the table. If k is the kinetic energy of the chain in joule as it completely slips off the table, then the value of k is _________.
(Take \(g = 10 \text{ m/s}^2\))
Two persons A and B perform same amount of work in moving a body through a certain distance d with application of forces acting at angles 45\(^\circ\) and 60\(^\circ\) with the direction of displacement respectively. The ratio of force applied by person A to the force applied by person B is \(\frac{1}{\sqrt{x}}\). The value of x is ________.
A block moving horizontally on a smooth surface with a speed of \( 40 \, ms^{-1} \) splits into two equal parts. If one of the parts moves at \( 60 \, ms^{-1} \) in the same direction, then the fractional change in the kinetic energy will be \( x : 4 \) where \( x = \dots\dots\dots \).
Two particles having masses 4 g and 16 g respectively are moving with equal kinetic energies. The ratio of the magnitudes of their linear momentum is n : 2. The value of n will be ________ .
The potential energy (U) of a diatomic molecule is $U = \frac{\alpha}{r^{10}} - \frac{\beta}{r^5} - 3$. The equilibrium distance between two atoms will be $\left( \frac{2\alpha}{\beta} \right)^{\frac{a}{b}}$ , where a = _________.
A ball of mass 4 kg, moving with a velocity of 10 ms\(^{-1}\), collides with a spring of length 8 m and force constant 100 Nm\(^{-1}\). The length of the compressed spring is x m. The value of x, to the nearest integer, is __________.

Given below is the plot of a potential energy function U(x) for a system, in which a particle is in one dimensional motion, while a conservative force F(x) acts on it. Suppose that $E_{mech} = 8$ J, the incorrect statement for this system is :

[ where K.E. = kinetic energy ] 
 

An automobile of mass 'm' accelerates starting from origin and initially at rest, while the engine supplies constant power P. The position is given as a function of time by:

A small block slides down from the top of hemisphere of radius R=3 m as shown in the figure. The height 'h' at which the block will lose contact with the surface of the sphere is ________ m. (Assume there is no friction between the block and the hemisphere) 

 

A pendulum bob has a speed of 3 m/s at its lowest position. The pendulum is 50 cm long. The speed of bob, when the length makes an angle of $60^\circ$ to the vertical will be ($g = 10 \text{ m/s}^2$) ________ m/s.
A constant power delivering machine has towed a box, which was initially at rest, along a horizontal straight line. The distance moved by the box in time 't' is proportional to :

As shown in the figure, a particle of mass 10 kg is placed at a point A. When the particle is slightly displaced to its right, it starts moving and reaches the point B. The speed of the particle at B is x m/s. (Take g = 10 m/s²) The value of 'x' to the nearest integer is __________. [Note: Usually $h_A = 10$m and $h_B = 5$m in this problem] 

Two solids A and B of mass 1 kg and 2 kg respectively are moving with equal linear momentum. The ratio of their kinetic energies (K.E.)A : (K.E.)B will be A/1, so the value of A will be ______
Two waves are simultaneously passing through a string and their equations are :
\(y_1 = A_1 \sin k(x - vt), y_2 = A_2 \sin k(x-vt+x_0)\). Given amplitudes \(A_1 = 12\) mm and \(A_2 = 5\) mm, \(x_0=3.5\) cm and wave number \(k=6.28\) cm\(^{-1}\). The amplitude of resulting wave will be __________ mm.
Two travelling waves produces a standing wave represented by equation. \(y = 1.0 \text{ mm} \cos(1.57 \text{ cm}^{-1})x \sin(78.5 \text{ s}^{-1})t\). The node closest to the origin in the region \(x>0\) will be at \(x = \)_________ cm.
Two cars X and Y are approaching each other with velocities 36 km/h and 72 km/h respectively. The frequency of a whistle sound as emitted by a passenger in car X, heard by the passenger in car Y is 1320 Hz. If the velocity of sound in air is 340 m/s, the actual frequency of the whistle sound produced is _________ Hz.
A tuning fork is vibrating at 250 Hz. The length of the shortest closed organ pipe that will resonate with the tuning fork will be _________ cm. (Take speed of sound in air as 340 ms\(^{-1}\))
A wire having a linear mass density \( 9.0 \times 10^{-4} \, kg/m \) is stretched between two rigid supports with a tension of \( 900 \, N \). The wire resonates at a frequency of \( 500 \, Hz \). The next higher frequency at which the same wire resonates is \( 550 \, Hz \). The length of the wire is \(\dots\dots\dots\) m.