NEB Question Browser

In an experiment on photoelectric effect, the graph between maximum kinetic energy and frequency of incident radiation on the metal surface is found to be straight line as shown in the figure.

Calculate:

i) Threshold frequency.
ii) Planck's constant.
iii) Work function of metal in eV.

In Young's double slit experiment, bright and dark bands are formed on a screen due to interference of light.

i) Define interference of light.
ii) Calculate the fringe width (β).
iii) When the whole apparatus is immersed in a liquid, what will be the effect on the fringe width?

Define root mean square value of AC.

When the torque acting upon a system is zero which of the following will be constant?

Bernoulli's Principle is based on the law of conservation of

An ideal gas is taken through series of changes represented in the diagram below. The net work done by the gas at the end of the cycle is equal to

Define radius of gyration.

A physics teacher stands on a freely rotating platform. He holds a dumbbell in each hand of his outstretched arms while a student gives him a push until his angular velocity reaches 1.5 rad/s. When the freely spinning teacher pulls his hands in close to his body, his angular velocity increases to 5.0 rad/s. What is the ratio of his final kinetic energy to initial kinetic energy?

According to Stoke's law, when a ball of radius r is falling in a viscous fluid, the viscous force produced is equal to

where symbols have their usual meanings.

i) Define coefficient of viscosity.
ii) How can you use this method to determine the coefficient of viscosity of a liquid? Explain.

A horizontal pipe of 25 cm² cross section carries water at a velocity of 3 m/s. The pipe feeds into a smaller pipe with a cross section of 15 cm². Determine the pressure change that occurs on going from the larger-diameter pipe to the smaller pipe.

i) Write down Newton's formula for the velocity of sound in a gas medium with its discrepancy.
ii) Obtain Laplace's corrected formula.
iii) Explain why sound waves are also called pressure waves.

Self inductance of a coil varies as

State first law of thermodynamics.

P-waves are

Kirchhoff's voltage law of electrical circuit is based on the principle of conservation of

The figure shows the variation of thermoemf with the temperature of the hot junction, when the cold junction is at 0°C.

i) What is thermoelectric effect?
ii) Define θₙ and θᵢ.
iii) What will be the effect on θᵢ if we shift the cold junction to −10°C?
iv) Give one of the applications of such thermocouple.

The displacement (y) of a particle executing simple harmonic motion is

y = r sin ωt,

where r is the amplitude of vibration.

i) Define amplitude.
ii) Calculate the acceleration of the motion.

Biot-Savart law gives the magnitude of magnetic field produced by a current carrying conductor.

i) State Biot-Savart law.
ii) Use Biot-Savart law to calculate the magnetic field of a circular current carrying coil at its centre.
iii) Also determine the direction of the magnetic field in this case.

When a P-type semiconductor is suitably joined to an N-type semiconductor, a p-n junction is formed.

i) Describe the formation of potential barrier.
ii) When the p-n junction diode is forward biased, a large current flows, why?

The given figure shows the first overtone of a stretched string of length l.

i) Define harmonics and overtone.
ii) Calculate the frequency of this mode.
iii) If the tension of the string is increased 4 times, what will be the frequency of this mode?