List of practice Questions

If 5 L of an ideal gas at a constant external pressure of 2 atm expands isothermally to a final volume of \( X \) L, the system does a work of -2,026.4 J. \( X \) (in L) is
The hole and the free electron concentrations in pure silicon at room temperature are given by $1.4 \times 10^{16}\ \mathrm{m}^{-3}$. When doped with indium, and the hole concentration becomes $4 \times 10^{22}\ \mathrm{m}^{-3}$, the electron concentration is
When A = 0 and B = 1, the output is 0 for
The refractive index of ionosphere is
The angular momentum of electron in H atom in a particular n state is $\frac{h}{\pi}$. What is the energy in J required to excite the electron from this particular n state to (n+1) state?
Which one of the following indicates correct order of atomic size of the given elements?
The elements with metallic nature in the following are C, Si, Ge, Sn, Pb.
The axial field \( B_A \) and equatorial field \( B_E \) due to a short bar magnet at equal distances are related as:
Total emf induced in a coil with \( N \) turns and changing magnetic flux \( \frac{d\phi_B}{dt} \) is:
A 25 \(\Omega\) resistor and inductor in series with voltage \( V = 100\sin(100\pi t) \), impedance = 50 Ω. Find average power:
A charge oscillating at 750 kHz produces EM waves of frequency:
In a photoelectric graph of stopping potential vs frequency, straight line makes angle \( \theta \) with Y-axis. Then \( \tan \theta = \):
In hydrogen spectrum, the shortest wavelengths of Lyman and Balmer series are $\lambda_1$ and $\lambda_2$ respectively. The Rydberg constant of hydrogen is
The particle having zero mass is
Electron of charge \( e \) moves in hydrogen atom (radius \( r \)). Coulomb force between nucleus and electron is:
(Here \( K = \frac{1}{4 \pi \varepsilon_0} \))
Potential \( V = \frac{1}{2}(y^2 - 4x) \). Electric field at \( x = 1 \, \text{m}, y = 1 \, \text{m} \) is:
A parallel plate capacitor is filled with mica (thickness \(1 \times 10^{-3}\) m) and fiber (thickness \(0.5 \times 10^{-3}\) m). Dielectric constants: mica = 8, fiber = 2.5. If fiber breaks at \(6.4 \times 10^6 \, \text{V/m}\), max voltage is:
Two square plates A and B have same thickness \( t \), material. B’s side is twice A’s. Find \( \frac{R_A}{R_B} \):
Two square plates A and B have same thickness t,
In the circuit with 6 V battery and resistors of 2Ω each, current is 2 A. Find potential at B with respect to A.
circuit with 6 V battery and resistors of 2 each
A flexible wire loop carrying current is placed in external magnetic field. Its shape becomes:
Distance moved by a charged particle in magnetic field (with parallel velocity component) in one rotation is:
A vessel withstands 100 atm. It's filled with hydrogen at 27°C (300 K) to 20 atm. Find temp. at which pressure becomes 100 atm.
The relation between absolute temperature (T) and pressure (P) in adiabatic process is:
If average KE of gas molecule at \( 27^\circ C \) is \( 3.3 \times 10^{-20} \, \text{J} \), find KE at \( 127^\circ C \):
A standing wave having 3 nodes and 2 antinodes is formed between two atoms separated by a distance of \( 1.21 \, \text{\AA} \). The wavelength of the wave is: