List of top Physics Questions

100 gm of copper is heated to increase its temperature by $21^\circ C$. If the same amount of heat is given to 50 gm of water, then the rise in its temperature is (Specific heat of Cu = $400~J~kg^{-1}K^{-1}$, Water = $4200~J~kg^{-1}K^{-1}$):

A thermally insulated vessel contains an ideal gas of molecular weight M and specific heat ratio $\gamma$. If it is moving with speed V and suddenly brought to rest, the temperature increase is:

In a thermodynamic process, a gas releases 20 J of heat and 10 J of work is done on the gas. If initial internal energy was 40 J, the final internal energy is:

A wire can sustain a weight of 100 kg before it breaks. The wire is cut into two equal parts. Without breaking each part can hold weight up to:

Two particles of masses $m_1$ and $m_2$ ($m_1 > m_2$) are separated by a distance 'd'. When the positions of the two particles are interchanged, the shift in the centre of mass is:

A uniform rod of mass 20 kg and length 1.6 m is pivoted at its one end and can swing freely in the vertical plane. The angular acceleration of the rod just after the rod is released from rest in the horizontal position is:

The figure shows the revolution of the planet (P) around the sun (S) in an elliptical orbit. Which of the following statements is true regarding time taken?

Which of the following statements are correct for a particle in simple harmonic motion? I. Its velocity-displacement graph is a parabola. II. Its velocity-time graph is sinusoidal. III. Its velocity-acceleration graph is an ellipse.

The potential energy of a particle of mass 1 kg which is in simple harmonic motion along X-axis is given by $U(x)=4(1-\cos 2x)$. The time period of oscillations is:

A man weighing 50 kg is in a lift moving down with an acceleration of $2.8 m s^{-2}$. The force exerted by the floor on him is:

A body is moving in a straight line with constant power. The distance moved by the body in time t is proportional to:

The percentage decrease in range of a projectile projected at $30^\circ$ when compared to maximum range is:

A particle moves with velocity $v = at - bt^2$ where a and b are constants. The acceleration becomes zero at:

A machine gun of mass 20 kg fires bullets, each of 40 g at the rate of 120 bullets per minute with a speed of $100 m s^{-1}$. The recoil velocity of the gun is:

Two identical balls P and Q having velocities $0.7 m s^{-1}$ and $-0.4 m s^{-1}$ respectively are colliding in one dimension elastically. The velocities of P and Q after the collision respectively are:

A particle under constant acceleration covers the first half of the total distance in time $t_1$ and remaining in time $t_2$. Then:

If force, $F=kv^{n}$ (k is constant) and power delivered is independent of velocity 'v', then n equals to:

In an electromagnetic wave in vacuum, the relation between peak electric field E_0 and magnetic field B_0 is:

For a convex lens, magnifications m_1 and m_2 correspond to object distances u_1 and u_2. The focal length is:

The threshold frequency for a certain photosensitive metal surface is _0. When light of frequency 2_0 is incident on the surface, the maximum velocity of the emitted photoelectrons is v_1. If the frequency is increased to 5_0, the maximum velocity becomes v_2. The ratio v_1 : v_2 is:

In a nuclear reactor, heavy water (D_2O) is used as a moderator. Its main function is to:

A wire of resistance R is stretched uniformly to double its original length. The new resistance will be:

Three capacitors of capacitances \(2\,\mu F\), \(3\,\mu F\), and \(6\,\mu F\) are connected in series. The equivalent capacitance is:

The electric potential at a point on the axis of an electric dipole at a distance r from its center is proportional to:

Doping a semiconductor with a trivalent impurity results in: