ISC (Science) ISC Class 12 - CISCE Question Bank Solutions for Physics (Theory)

Using Bohr's postulates derive the expression for the radius of n^th orbit of the electron.

Ratio of longest to shortest wavelength in Balmer series is ______.

With an increase in the temperature, the electrical conductivity of a semiconductor ______.

What type of semiconductor is obtained when a crystal of silicon is doped with a trivalent element?

How much is the angular momentum of an electron when it is orbiting in the second Bohr orbit of hydrogen atom?

Using Bohr’s Theory of hydrogen atom, obtain an expression for the velocity of an electron in the n^th orbit of an atom.

The majority charge carriers in a P-type semiconductor are ______.

The figure below is the Energy level diagram for the Hydrogen atom. Study the transitions shown and answer the following question:

1. State the type of spectrum obtained.
2. Name the series of spectrum obtained.

On the basis of Bohr's theory, derive an expression for the radius of the n^th orbit of an electron of hydrogen atom.

State the Bohr's postulate of angular momentum of an electron.

What is the velocity of an electron in the 3rd orbit of hydrogen atom if its velocity in the 1^st orbit is v₀?

The de Broglie wavelength of an electron in the first Bohr’s orbit of hydrogen atom is equal to ______.

A rectangular loop of area 5m2, has 50 turns and carries a current of 1A. It is hold in a uniform magnetic field of 0.1T, at an angle of 30°. Calculate the torque experienced by the coil. 

Identify the part of the electromagnetic spectrum which is suitable for radar system used in aircraft navigation.

State Moseley's law

State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of the visible spectrum.

Name three radiations and their wavelength range which are invisible and beyond the violet end of the visible spectrum.

Name the radiation which can be detected by thermopile.

To which regions of the electromagnetic spectrum do the following wavelengths belong: 
(a) 250 nm 
(b) 1500 nm 

Arrange the following electromagnetic waves in increasing order of their frequencies (i.e. begin with the lowest frequency):
Visible light, y rays, X rays, microwaves, radio waves, infrared radiations, and ultraviolet radiation.