List of top Physics Questions asked in JEE Main

A uniform disc with mass M = 4 kg and radius R = 10 cm is mounted on a fixed horizontal axle as shown in figure.
A uniform disc with mass M 
A block with mass m = 2 kg hangs from a massless cord that is wrapped around the rim of the disc. During the fall of the block, the cord does not slip and there is no friction at the axle. The tension in the cord is _____ N. (Take g = 10 ms–2)
Two masses \(M_1\) and \(M_2\) are tied together at the two ends of a light inextensible string that passes over a frictionless pulley. When the mass \(M_2\) is twice that of \(M_1\), the acceleration of the system is \(a_1\). When the mass \(M_2\) is thrice that of \(M_1\), the acceleration of the system is \(a_2\). The ratio \(\frac{a_1}{a_2}\) will be
A thin circular ring of mass M and radius R is rotating with a constant angular velocity 2 rad s–1 in a horizontal plane about an axis vertical to its plane and passing through the center of the ring. If two objects each of mass m be attached gently to the opposite ends of a diameter of ring, the ring will then rotate with an angular velocity (in rad s–1)
Time period of a simple pendulum in a stationary lift is ‘T’. If the lift accelerates with \(\frac{g}{6}\) vertically upwards then the time period will be (Where g = acceleration due to gravity)
As per given figures, two springs of spring constants k and 2k are connected to mass m. If the period of oscillation in figure (a)is 3s, then the period of oscillation in figure (b) will be \(\sqrt x\) s. The value of \(x\) is _______
two springs of spring constants k and 2k are connected to mass m.
A thermally insulated vessel contains an ideal gas of molecular mass M and ratio of specific heats 1.4. Vessel is moving with speed ν and is suddenly brought to rest. Assuming no heat is lost to the surrounding and vessel temperature of the gas increases by(R = universal gas constant
A uniform heavy rod of mass \(20\) kg, cross sectional area \(0.4\) \(m^2\) and length \(20\) \(m\) is hanging from a fixed support. Neglecting the lateral contraction, the elongation in the rod due to its own weight is \(x × 10^{–9}\) \(m\). The value of \(x\) is _____(Given Young’s modulus \(Y = 2 × 10^{11} Nm^{–2}\)and g = \(10\; ms^{–2})\)
A velocity selector consists of electric field \(\overrightarrow E=E\hat K\) and magnetic field \(\overrightarrow B=B\hat j\) with \(B = 12 \;mT\). The value of E required for an electron of energy \(728\) \(eV\) moving along the positive x-axis to pass undeflected is (Given, mass of electron = \(9.1 × 10^{–31}\) kg)

Given below two statements: One is labelled as Assertion (A) and other is labelled as Reason (R).
Assertion (A) : Non-polar materials do not have any permanent dipole moment.
Reason (R) :When a non-polar material is placed in an electric field, the centre of the positive charge distribution of it’s individual atom or molecule coincides with the centre of the negative charge distribution.
In the light of above statements, choose the most appropriate answer from the options given below.

Choose the correct statement for amplitude modulation :
A light ray is incident at an incident angle θ1 on the system of two plane mirrors M1 and M2 having an inclination angle 75° between them (as shown in figure). 
After reflecting from mirror M1 it gets reflected back by the mirror M2 with an angle of reflection 30°. The total deviation of the ray will be ________ degree.
A light ray is incident, at an incident angle θ1
An electron with speed υ and a photon with speed c have the same de-Broglie wavelength. If the kinetic energy and momentum of electron are Ee and pe and that of photon are Eph and pph respectively. Which of the following is correct?
In a vernier callipers, each cm on the main scale is divided into 20 equal parts. If tenth vernier scale division coincides with nineth main scale division. Then the value of vernier constant will be____ ×10–2 mm
A fighter jet is flying horizontally at a certain altitude with a speed of 200 ms–1. When it passes directly overhead an anti-aircraft gun, a bullet is fired from the gun, at an angle θ with the horizontal, to hit the jet. If the bullet speed is 400 m/s, the value of θ will be ____°

The elastic behavior of material for linear stress and linear strain, is shown in the figure. The energy density for a linear strain of 5×10–4 is ____ kJ/m3. Assume that material is elastic up to the linear strain of 5×10–4
elastic behavior of material for linear stress and linear strain

The magnetic flux through a coil perpendicular to its plane is varying according to the relation \(\varphi = 5t^3 + 4t^2 + 2t - 5\) Weber. If the resistance of the coil is 5 ohm, then the induced current through the coil at t = 2 s will be,
A block ‘A’ takes 2 s to slide down a frictionless incline of 30° and length ‘l’, kept inside a lift going up with uniform velocity ‘v’. If the incline is changed to 45°, the time taken by the block, to slide down the incline, will be approximately
Two capacitors having capacitance C1 and C2 respectively are connected as shown in figure. Initially, capacitor C1 is charged to a potential difference V volt by a battery. The battery is then removed and the charged capacitor C1 is now connected to uncharged capacitor C2 by closing the switch S. The amount of charge on the capacitor C2, after equilibrium, is
Two capacitors having capacitance C1 and C2

The velocity of the bullet becomes one third after it penetrates 4 cm in a wooden block. Assuming that bullet is facing a constant resistance during its motion in the block. The bullet stops completely after travelling at (4 + x) cm inside the block. The value of x is

How many alpha and beta particles are emitted when Uranium 92U238 decays to lead 82Pb206
A person is standing in an elevator. In which situation, he experiences weight loss?
A ball of mass 0.5 kg is dropped from the height of 10 m. The height, at which the magnitude of velocity becomes equal to the magnitude of acceleration due to gravity, is ___ m.
[Use g = 10 m/s2]
The elongation of a wire on the surface of the earth is 10–4m. The same wire of same dimensions is elongated by 6 × 10–5m on another planet. The acceleration due to gravity on the planet will be ___ ms–2. (Take acceleration due to gravity on the surface of earth = 10 ms–2)
A body of mass m is projected with velocity λve in vertically upward direction from the surface of the earth into space. It is given that ve is escape velocity and λ< 1. If air resistance is considered to be negligible, then the maximum height from the centre of earth, to which the body can go, will be:
(R : radius of earth)
An ideal fluid of density 800kgm–3, flows smoothly through a bent pipe (as shown in figure) that tapers in cross-sectional area from a to \(\frac{a}{2}\). The pressure difference between the wide and narrow sections of pipe is 4100 Pa. At wider section, the velocity of fluid is\(\frac{\sqrt{x}}{6}\) ms1 for x=_______. (Given g=10 ms-2)
ideal fluid of density 800kgm–3