List of top Physics Questions

Total emf induced in a coil with \( N \) turns and changing magnetic flux \( \frac{d\phi_B}{dt} \) is:
Potential \( V = \frac{1}{2}(y^2 - 4x) \). Electric field at \( x = 1 \, \text{m}, y = 1 \, \text{m} \) is:
Electron of charge \( e \) moves in hydrogen atom (radius \( r \)). Coulomb force between nucleus and electron is:
(Here \( K = \frac{1}{4 \pi \varepsilon_0} \))
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 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
The relation between absolute temperature (T) and pressure (P) in adiabatic process 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.
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:
Telescope has objective diameter 250 cm. For wavelength \( \lambda = 600 \, \text{nm} \), the limit of resolution is:
In a Carnot engine, if the temperatures of the source and sink are both decreased by 100 K, the efficiency:
A steel tape of 300 cm is graduated at \( 27^\circ \text{C} \). A steel rod measured to be 110 cm at \( 50^\circ \text{C} \) with this tape has actual length (given \( \alpha_{\text{steel}} = 1.2 \times 10^{-5} \, \text{K}^{-1} \)):
A particle initially at the mean position is executing simple harmonic motion with an angular frequency \( \frac{\pi}{4} \, \text{rad/s} \). The ratio of the distances travelled by the particle in the first second and second second is:
A rectangular metallic block of size \( 40 \, \text{mm} \times 20 \, \text{mm} \) is pulled with a force of \( 50 \, \text{kN} \). The strain in the block is:
(Shear modulus \( = 40 \times 10^9 \, \text{Nm}^{-2} \))
A spherical portion A of radius \( R \) is removed from a solid sphere B of radius \( 2R \), both centered. The ratio of moments of inertia of remaining part to original is:
A disc of moment of inertia \( 3.5 \, \text{kg m}^2 \) is rotating at \( 30 \, \text{rad/s} \). Torque to stop it in 5 seconds is:
If a body has a potential energy of \( (4x^2 + 2x) \, \text{J} \) at height 2 m, then the force acting on it is:
Force is the mutual interaction between bodies according to:
A freely falling body has attained a velocity of \( 2 \, \text{ms}^{-1} \). If it is opposed by air resistance, total distance before stopping is:
A body moves with uniform speed of \( 20 \text{ ms}^{-1} \) in a horizontal circle. What is the change in velocity after half revolution?
A motor vehicle of mass 1000 kg is moving on a circular road having banking angle \( 30^\circ \) and coefficient of friction 0.2. Then the normal reaction force on the motor vehicle is about:
(Acceleration due to gravity = \( 10 \, \text{ms}^{-2} \))
The dimensional formula of a physical quantity represented by \( \frac{e^2}{4 \varepsilon_0 h} \) is:
Where \( e \) is the charge of the electron, \( \varepsilon_0 \) is the permittivity of free space, and \( h \) is Planck's constant.