List of top Physics Questions

A metal surface is illuminated by a radiation of wavelength 4500 Å. The rejected photo-electron enters a constant magnetic field of 2 mT making an angle of 90° with the magnetic field. If it starts revolving in a circular path of radius 2 mm, the work function of the metal is approximately:

The equation $\lambda=\frac{1227}{ x } nm$ can be used to find the de-Brogli wavelength of an electron In this equation $x$ stands for : Where, $m =$ mass of electron $P =$ momentum of electron $K =$ Kinetic energy of electron $V=$ Accelerating potential in volts for electron

Two streams of photons, possessing energies equal to five and ten times the work function of metal are incident on the metal surface successively. The ratio of maximum velocities of the photoelectron emitted, in the two cases respectively, will be

If the electric potential at any point (x, y, z)m in space is given by V = 3x² volt. The electric field at the point (1, 0, 3)m will be

A vessel contains 16 g of hydrogen and 128 g of oxygen at standard temperature and pressure. The volume of the vessel in cm³ is:

If a wave gets refracted into a denser medium, then which of the following is true?

A water drop of radius 1 cm is broken into 729 equal droplets. If surface tension of water is 75 dyne/cm, then the gain in surface energy upto first decimal place will be :
(Given $\pi$ = 3.14)

Two planets, A and B, orbit around a star such that the time period of A is 8 times the time period of B. The ratio of orbital velocities of the planets A and B is

The light of two different frequencies whose photons have energies 3.8 eV and 1.4 eV respectively, illuminate a metallic surface whose work function is 0.6 eV successively. The ratio of maximum speeds of emitted electrons for the two frequencies respectively will be

Two point charges q₁ and q₂ are ‘l’ distance apart. If one of the charges is doubled and distance between them is halved, the magnitude of force becomes n times, where n is

Draw a neat, labelled diagram of a suspended coil type moving coil galvanometer. The initial pressure and volume of a gas enclosed in a cylinder are 2 × 10^5 N/m² and 6 × 10^{-3} m³ respectively. If the work done in compressing the gas at constant pressure is 150 J, find the final volume of the gas.

What is a rectifier? With the help of a neat circuit diagram, explain the working of a half wave rectifier.

Explain de Broglie wavelength. Obtain an expression for de Broglie wavelength of wave associated with material particles. The photoelectric work function for a metal is 4.2 eV. Find the threshold wavelength.

Define second's pendulum. Derive a formula for the length of second's pendulum. A particle performing linear S.H.M. has maximum velocity 25 cm/s and maximum acceleration 100 cm/s². Find period of oscillations.

A parallel plate capacitor filled with air has an area of 6 cm² and plate separation of 3 mm. Calculate its capacitance.

An emf of 91 mV is induced in the windings of a coil, when the current in a nearby coil is increasing at the rate of 1.3 A/s, what is the mutual inductance (M) of the two coils in mH?

Derive an expression for a pressure exerted by a gas on the basis of kinetic theory of gases.

Two cells of emf 4V and 2V having respective internal resistance of 1 Ω and 2 Ω are connected in parallel, so as to send current in the same direction through an external resistance of 5 Ω. Find the current through the external resistance.

Determine the shortest wavelengths of Balmer and Paschen series. Given the limit for Lyman series is 912 Å.

Calculate the value of magnetic field at a distance of 3 cm from a very long, straight wire carrying a current of 6A.

Derive an expression for emf ($ e $) generated in a conductor of length ($ l $) moving in uniform magnetic field ($ B $) with uniform velocity ($ v $) along x-axis.

Derive an expression for terminal velocity of a spherical object falling under gravity through a viscous medium.

Prove that the frequency of beats is equal to the difference between the frequencies of the two sound notes giving rise to beats.

With the help of a neat diagram, explain the reflection of light on a plane reflecting surface.

Define:
(a) Inductive reactance
(b) Capacitive reactance
(c) Impedance