List of top Physics Questions

Consider a pair of insulating blocks with thermal resistances \( R_1 \) and \( R_2 \) as shown in the figure. The temperature \( \theta \) at the boundary between the two blocks is:
A solid sphere is rotating in free space. If the radius of the sphere is increased keeping the mass the same, which one of the following will not be affected?
A mass of 0.5 kg moving with a speed of 1.5 m/s on a horizontal smooth surface, collides with a nearly weightless spring of force constant \( k = 50 \, \text{N/m} \). The maximum compression of the spring would be:
The figure below shows currents in a part of electric circuit. The current \( i \) is:
The equivalent capacitance of the combination of the capacitors is:
The half-life period and the mean life period of a radioactive element are denoted respectively by \( T_h \) and \( T_m \). Then:
An electric dipole is kept in a uniform electric field. It experiences:
In a common base mode of a transistor, the collector current is 5.488 mA for an emitter current of 5.60 mA. The value of the base current amplification factor \( \beta \) will be:
A person swims in a river aiming to reach exactly on the opposite point on the bank of a river. His speed of swimming is 0.5 m/s at an angle of 120° with the direction of flow of water. The speed of water is:
The magnetic field at a distance \( r \) from a long wire carrying current is 0.4 tesla. The magnetic field at a distance \( 2r \) is:
The velocity-time graph of a body moving in a straight line is shown in the figure. Find the displacement and distance travelled by the body in 10 seconds.
A point charge \( q \) is rotated along a circle in the electric field generated by another point charge \( Q \). The work done by the electric field on the rotating charge in one complete revolution is:
Radioactive element decays to form a stable nuclide, then the rate of decay of reactant is shown by:
If the kinetic energy of a free electron doubles, its de-Broglie wavelength changes by the factor:
The ratio of the energies of the hydrogen atom in its first to second excited states is:
Which of the following gates will have an output of 1?
Two thin lenses are in contact and the focal length of the combination is 80 cm. If the focal length of one lens is 20 cm, then the power of the other lens will be:
The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then:
The radius of the first zone in a zone plate of focal length 40 cm for light of wavelength 4000 Å is:
Which of the following is an optically active substance?
The acceleration of a frame of reference, fixed on the earth’s surface at the equator and rotating with the earth, once a day will be:
If a particle is fixed on a rotating frame of reference, the fictitious force acting on the particle will be:
Maximum acceleration in SHM
What is the phase difference between velocity and acceleration of a particle executing SHM?
Given the potential difference \( V(x) = -x^2 y \) volts, find the electric field at the point (1, 2).