List of top Physics Questions

The magnetic field at the point of intersection of diagonals of a square loop of side $L$ carrying a current $I$ is
Mixed $He^{+}$ and $O^{2 +}$ ions (mass of $H e^{+}=4 \, amu \, and \, that \, of \, O^{2 +}=16 \, amu$ ) beam passes a region of constant perpendicular magnetic field. If kinetic energy of all the ions is same, then
A current $I$ flows along the length of an infinitely long, straight, thin-walled pipe. Then
A $ 1\, kg $ block situated on a rough incline is connected to a spring of negligible mass having spring constant $ 100\, N\,m^{-1} $ as shown in the figure.
The block is released from rest with the spring in the unstretched position. The block moves $ 10\, cm $ down the incline before coming to rest. The coefficient of friction between the block and the incline is (Take $ g = 10\, ms^{-2} $ and assume that the pulley is frictionless)
A 1.0 mH inductance, a 10 $\mu F$ capacitance and a 5.0 ohm resistance are connected in series to an a.c. source. It is found that the inductor and the capacitor show equal reactances. The reactance should be nearest to
A $0.5\, kg$ ball is thrown vertically up with $14 \,m s^{-1}$. It attains a height of $8\,m$. The energy dissipated by air drag acting on the ball during ascent is
A $0.2\, k\Omega$ resistor and $15\,\mu F$ capacitor are connected in series to a $220\,V$, $50\,Hz$ ac source. The impedance of the circuit is
Clouds appear to float in air due to
$^{}_{92}U^{238}$ on absorbing a neutron goes over to $^{}_{92}U^{239} .$ This nucleus emits an electron to go over to neptunium which on further emitting an electron goes over to plutonium. The resulting plutonium can be expressed as.
A small ball of density $\rho$ is immersed in a liquid of density $(\sigma > \rho)$ to a depth h and released. The height above the surface of water up to the ball will jump is
The S.I Unit of pressure 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
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
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}}$
Longitudinal wave can travel in
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 $g=10 \, m \, s^{- 2}$ )