List of top Physics Questions

A Carnot engine operates between 400 K and 300 K. Its efficiency is:
The moment of inertia of a thin ring about its diameter is:
In Young's double-slit experiment, the slits are 0.2 mm apart and the screen is 1 m away. The distance between the central bright fringe and the third bright fringe is 1.5 cm. The wavelength of light used is:
Two point charges \(+q\) and \(-q\) are placed at distance \(2a\) apart. The electric field intensity is zero at a point on the axis at distance \(x\) from the midpoint. Then \(x\) is:
The activity of a radioactive sample decreases to 25% of its initial value in 60 days. The half-life is:
A sound wave has frequency 500 Hz and wavelength 0.68 m. The speed of sound is:
A body weighs 50 N on the surface of Earth. Its weight at a height equal to the radius of Earth from the surface is:
Light of wavelength 600 nm is incident on a metal surface with work function 2 eV. The maximum kinetic energy of photoelectrons is:
A transformer has 500 turns in primary and 100 turns in secondary. If input voltage is 220 V AC, the output voltage is:
A stone is dropped from a height of 80 m. At the same instant, another stone is projected vertically upwards from the ground with a speed of 40 m/s. The time after which they meet is (\(g = 10\ \text{m/s}^2\)):
The potential energy of a particle of mass 2 kg moving along x-axis is given by \(U = (x^2 - 4x)\) J. The force acting on it at \(x = 3\) m is:
A uniform rod of length \(L\) and mass \(M\) is pivoted at one end and displaced by a small angle \(\theta\) from vertical. The time period of small oscillations is:
In a series LCR circuit at resonance, the voltage across the inductor is 100 V and across the capacitor is 100 V. The voltage across the resistor is:
The de Broglie wavelength of an electron accelerated through 100 V is approximately:
A charged particle enters a uniform magnetic field perpendicular to its velocity. If the field is suddenly doubled, the radius of its path becomes:
A particle moves with uniform acceleration along a straight line. The average velocity over an interval is equal to the instantaneous velocity at:
The unit of electric field intensity is:
In a p-n junction diode, the reverse saturation current doubles for every rise in temperature of:
The work done by a conservative force in a closed path is:
The half-life of a radioactive element is 8 days. The fraction remaining after 32 days is:
A convex lens of focal length 20 cm forms a real image at 30 cm from the lens. The object distance is:
A resistor of \(10\,\Omega\) and an inductor of \(0.1\,\text{H}\) are connected in series to a \(100\ \text{V}, 50\ \text{Hz}\) AC source. The impedance of the circuit is:
The escape velocity from the surface of Earth is 11.2 km/s. If the radius of Earth is doubled and mass remains the same, the new escape velocity will be:
In Young's double-slit experiment, the fringe width is 0.6 mm. If the distance between the slits and screen is doubled, and the separation between slits is halved, the new fringe width will be:
The dimensional formula for magnetic flux is: