NEB Question Browser

Calculate the work function for sodium.

From the graph determine the maximum frequency of incident radiation that can cause a photoelectric effect.

State the two Kirchhoff’s laws for electrical circuits.

State the principle of the Potentiometer. A potentiometer is also called a voltmeter of infinite resistance, why?

A horizontal beam of electrons moving with velocity v passes between two parallel plates as shown in the figure.

i) Describe the motion of electron and show that the path followed by it is parabolic.
ii) What is cross field? Write one use of cross field.

The given figure shows the LCR series circuit.

i) Obtain the expression for impedance of the circuit.
ii) What is resonance in LCR series circuit?
iii) Calculate the resonant frequency.
iv) What is quality factor of the circuit?

i) State Bragg's law.
ii) The largest distance between the inter atomic planes of crystal is 10 Å. What is the upper limit for the wavelength of X-rays which can be used to study the crystal?

Obtain the efficiency of a heat engine.

Obtain a relation for the energy stored in an inductor.

A step down transformer converts a voltage of 2200 Volt into 220 Volt in the transmission line. Number of turns in the primary coil is 5000. Efficiency of the transformer is 90% and its output power is 8 KW. Calculate:

i) Number of turns in the secondary coil.
ii) Input power.

A particle executes SHM. Its initial position is the mean position. The kinetic energy of a particle against time period is represented by the curve.

What is the significance of the Clausius statement of the second law of thermodynamics?

If a uniform spring is cut in half, what is the force constant of each half? How would the frequency of half spring differ from that using the same mass and entire spring?

Apply the first law of thermodynamics to relate the two specific heat capacities of a gas, i.e.

If the source of sound and the listener move in the same direction with same velocity equal to half the velocity of sound, what is the change in frequency?

The given figure represents a wavefront AB moving in air and incident on a plane glass surface XY. Its position after refraction through the glass slab is CD. The refractive index of glass with respect to air will be equal to:

The region of initiation of seismic energy within the earth is called

Calculate the moment of inertia of a thin uniform rod about an axis passing through its centre and perpendicular to its length.

Bohr's atomic model is based on quantum theory of radiation.

i) Write the postulates of Bohr's atomic model.
ii) Calculate the radius of nᵗʰ orbit of H-atom using Bohr's postulates.

Lenz law gives the direction of induced emf.

i) State Lenz law.
ii) Explain how this law is in accordance with the law of conservation of energy.