List of top Physics Questions

Two particles of equal mass \( m \) go round a circle of radius \( R \) under the action of their mutual gravitational attraction. The speed of each particle is
The time dependence of a physical quantity \( P \) is given by \( P = P_0 e^{\alpha (-\alpha t^2)} \), where \( \alpha \) is a constant and \( t \) is time. The constant \( \alpha \) has dimensions of
If the potential energy of a gas molecule is \[ U = \frac{M}{r} - \frac{N}{r^2} \] where \( M \) and \( N \) are positive constants, then the potential energy at equilibrium must be
In the adjoining figure, the position-time graph of a particle of mass 0.1 kg is shown. The impulse at \( t = 2 \) s is
The centre of a wheel rolling on a plane surface moves with a speed \( v_0 \). A particle on the rim of the wheel at the same level as the centre will be moving at speed
A table fan rotating at a speed of 2400 rpm is switched off and the resulting variation of revolution per minute with time is shown in figure. The total number of revolutions of the fan before it comes to rest is
The pressure on a square plate is measured by measuring the force on the plate. If the maximum error in the measurement of force and length are 4% and 2%, then the maximum error in the measurement of pressure is
The dimensional formula of magnetic flux is
Two balls of equal masses are thrown upwards along the same vertical direction at an interval of 2 s, with the same initial velocity of 39.2 m/s. The two balls will collide at a height of
A copper wire of length 2.2 m and a steel wire of length 1.6 m, both of diameter 3.0 mm, are connected end to end. When stretched by a force, the elongation in length 0.50 m is produced in the copper wire. The stretching force is ( \( Y_{\text{cu}} = 1.1 \times 10^{11} \, \text{N/m}^2, Y_{\text{steel}} = 2.0 \times 10^{11} \, \text{N/m}^2 \))
If \( v_p, v_{\text{rms}}, v_p \) represent the mean speed, root mean square speed, and most probable speed of the molecules in an ideal monoatomic gas at temperature \( T \) and \( m \) is the mass of the molecule, then
If a progressive wave is represented as \[ y = 2 \sin \left( \pi \left( \frac{t}{2} - \frac{x}{4} \right) \right) \] where \( x \) is in meters and \( t \) is in seconds, then the distance traveled by the wave in 5 s is
The gravitational potential at a place varies inversely with \( x^2 \) (i.e., \( V = kx^2 \)), the gravitational field at that place is
If a radio-receiver amplifies all the signal frequencies equally well, it is said to have high
Mobilities of electrons and holes in a sample of intrinsic germanium at room temperature are \( 0.36 \, \text{m}^2 \, \text{V}^{-1} \, \text{s}^{-1} \) and \( 0.17 \, \text{m}^2 \, \text{V}^{-1} \, \text{s}^{-1} \), respectively. The electron and hole densities are each equal to \( 2.5 \times 10^{19} \, \text{m}^{-3} \). The electrical conductivity of germanium is
An element with atomic number \( Z = 11 \) emits \( K_{\alpha} \)-X-ray of wavelength \( \lambda \). The atomic number which emits \( K_{\alpha} \)-X-ray of wavelength \( 4\lambda \) is
The amplitude of an electromagnetic wave in vacuum is doubled with no other changes made to the wave. As a result of this doubling of the amplitude, which of the following statement is correct?
The upper half of an inclined plane of inclination θ is perfectly smooth while lower half is rough. A block starting from rest at the top of the plane will again come to rest at the bottom, if the coefficient of friction between the block and lower half of the plane is given by
A, B and C are three points in a uniform electric field. The electric potential is
When a proton is released from rest in a room, it starts with an initial acceleration $a_0$ towards west. When it is projected towards north with a speed $v_0$ it moves with an initial acceleration 3$a_0$ toward west. The electric and magnetic fields in the room
A wave travelling in the +ve x-direction having displacement along y-direction as 1 m, wavelength 2π in and frequency of $\frac1{π}$Hz is represented by
If we study the vibration of a pipe open at both ends, then the following statement is not true
Two rings of radius $R$ and $nR$ made of same material have the ratio of moment of inertia about an axis passing through center is $1 : 8$. The value of $n$ is
A particle of mass ' $m$ ' is projected with a velocity $v$ making an angle of $30^{\circ}$ with the horizontal. The magnitude of angular momentum of the projectile about the point of projection when the particle is at its maximum height ' $h$ ' is
The velocity of a projectile at the initial point A is (2i+3j) m/s. Its velocity (in m/s) at point B is