List of top Physics Questions

A body is dropped from a height of $4 \,m$ on a surface. If in collision $25\%$ of energy is lost, then the height upto which it will rise after collision is
The relationship between Young's modulus $Y$, bulk modulus $K$ and modulus of rigidity $\eta$ is
8000 identical water drops combine together, to form a big drop. Then the ratio of the final surface energy to the initial surface energy of all the drops together is.
If plane surface of a piano convex lens is silvered, then it will behave as a
Longitudinal wave can travel in
A closed iron ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet is
The number of $\alpha$-particles and $\beta$-particles respectively emitted in the reaction $ {_{88}A^{196} -> _{78}B^{164}}$
Real gas behaves as an ideal gas, under which of the following conditions ?
A projectile is projected with speed $49\,ms^{-1}$ at an angle of $30^{\circ}$ with horizontal. The time taken by the projectile to reach the highest point is
The electrical conductivity of a semiconductor increases when electromagnetic radiation of wave length shorter than $2480\, nm$ is incident on it. The band gap (in $eV$) for semiconductor is
The potential difference across the collector of a transistor, used in common emitter mode is $1.5\, V$, with the collector resistance of $3\, k\Omega$, the emitter current is $[\beta = 50]$
A horizontal disk is rotating with angular velocity $\omega $ about a vertical axis passing through its centre. A ball is placed at the centre of groove and pushed slightly. The velocity of the ball when it comes out of the groove-
A car is moving with speed $20 \, \, \text{m s}^{- 1}$ on a circular path of radius $100 \, \, \text{m}$ . Its speed is increasing at a rate of $3 \, \text{m s}^{- 2}$ . The magnitude of the acceleration of the car at that moment is
The normal reaction on a body placed in a lift moving up with constant acceleration $2 \, m \, s^{- 1}$ is $120 \, N$ . Mass of the body is (Take $g=10 \, m \, s^{- 2}$ )
A block of mass $M$ is resting on a smooth horizontal plane. One end of a uniform rope of mass $\frac{M}{4}$ is fixed to the block, which pulled it in the horizontal direction by applying a force $F$ at the other ends. The tension in the middle of the rope is
For the arrangement in the figure, the particle $M_{1}$ attached to one end of a string which moves on a horizontal table in a circle of radius $=\frac{l}{2}$ (where $l$ is the length of the string) with the constant angular speed $\omega $ . The other end of the string attached to mass $M_{2}$ which rests on a vertical rod. When the rod collapse, the acceleration of mass $M_{2}$ at that instant
Three blocks are connected, as shown in the figure. Calculate the minimum force required to move the blocks with constant velocity. The co-efficient of friction at all surfaces is $0.25$ . [Assume that rod does not exerts force in vertical direction]
$\,^{221}_{87}$Ra undergoes radiorctive decay with a half life of 4 days. The probability that a Ra nucleus will disintegrate in 8 days is
$175$ calorie of heat is required to raise the temperature of $5$ mole of an ideal gas at constant pressure from $30^\circ\,C$ to $35^\circ\,C$. The amount of heat required to raise temperature of same gas from $30^\circ\,C$ to $35^\circ\,C$ constant volume will be
A resistor, capacitor and an inductor are connected in series and are in resonance. What is the phase difference between the supplied voltage and current ?
Capacitance of a spherical conductor of radius $R$ is proportional to
What is the relationship between electric field intensity $E$, current density $J$ and specific resistance $\rho$ ?
When a pentavalent impurity is added in Ge crystal then, what type of semiconductor is obtained ?
A person suffering from myopia should use a
At what temperature the root mean square velocity of a gas is twice of its root mean velocity at $27^{\circ} C $?