List of top Physics Questions asked in IIT JAM

A white dwarf star has volume \( V \) and contains \( N \) electrons so that the density of electrons is \( n = \frac{N}{V} \). Taking the temperature of the star to be 0 K, the average energy per electron in the star is \( \epsilon_0 = \frac{3h^2}{10m} (3n)^{2/3 \), where \( m \) is the mass of the electron. The electronic pressure in the star is:}

Consider two identical, finite, isolated systems of constant heat capacity \( C \) at temperatures \( T_1 \) and \( T_2 \) (\( T_1>T_2 \)). An engine works between them until their temperatures become equal. Taking into account that the work performed by the engine will be maximum (\( W_{\text{max}} \)) if the process is reversible (equivalently, the entropy change of the entire system is zero), the value of \( W_{\text{max}} \) is:

Consider Rydberg (hydrogen-like) atoms in a highly excited state with \( n \) around 300. The wavelength of radiation coming out of these atoms for transitions to the adjacent states lies in the range:

A plane in a cubic lattice makes intercepts of \( a, a/2 \) and \( 2a/3 \) with the three crystallographic axes, respectively. The Miller indices for this plane are:

For the three matrices given below, which one of the choices is correct?

Which of the following is due to inhomogeneous refractive index of earth’s atmosphere?

If the Boolean function \( Z = PQ + PQR + PQRS + PQRST + PQRSTU \), then \( Z \) is:

The dispersion relation for electromagnetic waves travelling in a plasma is given as \( \omega^2 = c^2k^2 + \omega_p^2 \), where \( c \) and \( \omega_p \) are constants. In this plasma, the group velocity is: