List of top Physics Questions

The total energy of an electron in an orbit of hydrogen atom is \( E \). The potential energy of the electron in the same orbit is
Two metal wires of same length, same area of cross-section have conductivities of their material \( \sigma_1 \) and \( \sigma_2 \). If they are connected in series, the effective conductivity is:
In the circuit, the cells are having negligible resistances. If the galvanometer shows null deflection, then the value of \( V \) is:
galvanometer shows null deflection,
If \( q \) is electric charge, \( B \) is magnetic field, \( R \) is the dee radius and \( m \) is the mass of ions, the kinetic energy of the ions in cyclotron is given by:
Curl the palm of your right hand around the circular wire with the fingers pointing in the direction of current and the thumb gives the direction of the magnetic field. In this case the upper side of the loop may be thought of as:
The Curie temperature \( T_c \) represents:
A resistor of 100 \( \Omega \), an inductor of \( \frac{25}{\pi} \) mH, and a capacitor of 0.1 \( \mu \)F are connected in series to an ac source. The impedance of the circuit is minimum for a frequency of:
Physically, the self-inductance plays the role of:
The frequency of a light ray is \( 6 \times 10^{14} \) Hz. Its frequency when it propagates in a medium of refractive index 1.5, will be:
Two charges \( Q \) and \( 4Q \) are separated by a distance of 6 cm. The distance of the point from \( 4Q \) at which the net electric field is zero is:
Inside a charged hollow sphere, at any point the electric field \( E \) and potential \( V \) are:
Two coherent light sources having intensity in the ratio 2:1 produce an interference pattern. Then the value of \( \frac{I_{\text{max}} - I_{\text{min}}}{I_{\text{max}} + I_{\text{min}}} \) will be:
If the rms speeds of helium and oxygen are equal, then the ratio of the temperatures of helium and oxygen is:
The equivalent capacitance between A and B in the given figure is:
equivalent capacitance between A and B
The ratio of radii of two wires is 1:2 and the density of their materials are in the ratio 1:4. If same tension is applied to both the wires then the ratio of the speed of transverse waves produced in them is:
A cylindrical rod made of aluminum has length 1 meter and diameter of 10 cm. The rod is subjected to a tensile force of 100 kN. The elongation in the rod is:
The phenomena of lowering freezing point of water by the application of pressure is known as:
A work of 166.28 J is done to adiabatically compress one mole of a gas. If the increase in the temperature of the gas is \( 8^\circ C \), the gas is:
In a Carnot’s engine, as the gas absorbs heat energy from the source, then the temperature of the source:
A uniform solid sphere of mass \( M \) and radius \( a \) is surrounded by a concentric uniform thin spherical shell of mass 0.5M and radius 1.5a. The gravitational potential energy of a unit mass kept at a distance of 2.5a from the center is:
A large open top water tank is completely filled with water. A small hole of diameter 4 mm is made 10 m below the water level. The flow rate of water through the hole is:
A steel ball of mass 200 g falls freely from a height of 20 m and bounces to a height of 10.8 m from the ground. If the energy lost in this process is absorbed by the ball, the rise in its temperature is:
The mechanical energy of a damped oscillator becomes half of its initial energy in 4 seconds. In another \( t \) seconds its mechanical energy becomes 12.5\% of its initial mechanical energy. Then \( t = \):
When an external force with angular frequency \( \omega_0 \) acts on a system of natural angular frequency \( \omega \), the system oscillates with angular frequency \( \omega_d \). The condition for the amplitude of oscillations to be maximum is:
A solid sphere is pushed on a horizontal surface such that it slides with a speed 3.5 m/s initially without rolling. The sphere will start rolling without slipping when its velocity becomes: