List of top Physics Questions

The force required to stop a body of mass 10 kg moving along a straight line path with a velocity of 10 ms\(^{-1}\) in a time of 10 s is:
A motor boat is moving in a river with velocity $\vec{v} = 7\hat{i} + 2\hat{j} - 5\hat{k}$ kms$^{-1}$. If the flow water offers resistive force $\vec{F} = 9\hat{i} + 3\hat{j} - 3\hat{k}$ N, then the power of the boat is
A car is travelling at \(30 \, \text{ms}^{-1}\) speed on a circular road of radius \(300 \, \text{m}\). If its speed is increasing at the rate of \(4 \, \text{ms}^{-2}\), then its acceleration is:
The density of a substance is 4 g/cc. In a system in which the unit of length is 5 cm and the unit of mass is 20 g, the density of the substance is:
A truck of mass \( M \) and a car of mass \( \frac{M}{10} \) moving with the same momentum are brought to halt by the application of the same breaking force. The ratio of the distances travelled by the truck and car before they come to stop is:
When A = 0 and B = 1, the output is 0 for
The refractive index of ionosphere 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
In hydrogen spectrum, the shortest wavelengths of Lyman and Balmer series are $\lambda_1$ and $\lambda_2$ respectively. The Rydberg constant of hydrogen is
A 25 \(\Omega\) resistor and inductor in series with voltage \( V = 100\sin(100\pi t) \), impedance = 50 Ω. Find average power:
The particle having zero mass is
The axial field \( B_A \) and equatorial field \( B_E \) due to a short bar magnet at equal distances are related as:
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 \( \tan \theta = \):
Total emf induced in a coil with \( N \) turns and changing magnetic flux \( \frac{d\phi_B}{dt} \) is:
Electron of charge \( e \) moves in hydrogen atom (radius \( r \)). Coulomb force between nucleus and electron is:
(Here \( K = \frac{1}{4 \pi \varepsilon_0} \))
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,
A flexible wire loop carrying current is placed in external magnetic field. Its shape becomes:
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
Distance moved by a charged particle in magnetic field (with parallel velocity component) in one rotation is:
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:
If average KE of gas molecule at \( 27^\circ C \) is \( 3.3 \times 10^{-20} \, \text{J} \), find KE at \( 127^\circ C \):
Telescope has objective diameter 250 cm. For wavelength \( \lambda = 600 \, \text{nm} \), the limit of resolution 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.