List of top Physics Questions

Two planets \( A \) and \( B \) have radii \( R \) and \( 1.5R \), and densities \( \rho \) and \( \frac{\rho}{2} \) respectively. The ratio of acceleration due to gravity at the surface of \( B \) to \( A \) is:
A planet in a distant solar system is 10 times more massive than Earth and its radius is 10 times smaller. Given that the escape velocity from Earth's surface is 11 km/s, the escape velocity from the planet’s surface would be:
In a Rutherford scattering experiment, when a projectile of charge \( Z_1 \) and mass \( M_1 \) approaches a target nucleus of charge \( Z_2 \) and mass \( M_2 \), the distance of closest approach is \( r_0 \). The energy of the projectile is:
If \( m \) is magnetic moment and \( B \) is the magnetic field, then the torque is given by:
A magnetic field does not interact with:
The radius of the current carrying circular coil is doubled keeping the current passing through it the same. Then the ratio of the magnetic field produced at the centre of the coil before the doubling of the radius to the magnetic field after doubling of the radius is:
Find the pole strength of a magnet of length 2 cm, if the magnetic field strength \( B \) at distance 10 cm from the centre of a magnet on the axial line of the magnet is \( 10^{-4} \, \text{T} \).
The properties of a material required to make permanent magnets are
A charged particle is moving in a uniform magnetic field \( \mathbf{B} = 2\hat{i} + 3\hat{j} \) T. If it has an acceleration of \( \mathbf{a} = \alpha\hat{i} - 4\hat{j} \) m/s², then the value of \( \alpha \) will be:
The free space inside a current carrying toroid is filled with a material of susceptibility \( \chi = 2 \times 10^{-2} \). The percentage increase in the value of magnetic field inside the toroid will be:
A conducting loop of radius \( \frac{10}{\sqrt{\pi}} \) cm is placed perpendicular to a uniform magnetic field of 0.5T. The magnetic field is decreased to zero in 0.5 s at a steady rate. The induced emf in the circular loop at 0.25s is:
Pick the correct answer from the following two statements:
(a) Virtual image can be seen with the eyes.
(b) Virtual image can be captured on the screen.
When light propagates through a given homogeneous medium, the velocities of
For a given pair of transparent media, the critical angle for which colour is maximum?
An equiconvex lens made of glass of refractive index \(\frac{3}{2}\) has focal length f in air. It is completely immersed in water of refractive index \(\frac{4}{3}\). The percentage change in the focal length is
The colour which has the highest critical angle of incidence is
The magnifying power of a telescope with tube length 60 cm is 5. Then the focal length of its eye piece is:
When $ 10^{19} $ electrons are removed from a neutral metal plate, the electric charge on it is
A dielectric of dielectric constant $ K $ is introduced such that half of its area of a capacitor of capacitance $ C $ is occupied by it. The new capacity is
State and prove the principle of conservation of angular momentum.
Answer the following questions:
What is the value of resistance for an ideal voltmeter?
In an experiment on a circuit, as shown in the figure, the voltmeter shows 8V reading. The resistance of the voltmeter is 
the voltmeter shows 8V reading
A galvanometer having a resistance of $ 8 \, \Omega $ is shunted by a wire of resistance $ 2 \, \Omega $. If the total current is 1 A, the part of it passing through the shunt will be
Two cells with the same emf $ E $ and different internal resistances $ r_1 $ and $ r_2 $ are connected in series to an external resistance $ R $. If the potential difference across the first cell is zero then the value of $ R $ is
The effect of an increase in temperature on the number of electrons in the conduction band (\( n_e \)) and the resistance of a semiconductor will be as follows: