ISC (Science) ISC Class 12 - CISCE Important Questions

The primary coil of a transformer has 60 turns whereas its secondary coil has 3000 turns.

If a 220 V ac voltage is applied to the primary coil, how much emf is induced in the secondary coil?

The primary coil of a transformer has 60 turns whereas its secondary coil has 3000 turns.

If a current of 5A flows in the primary coil, how much current will flow in a load in the secondary coil? State the assumption you have made regarding the transformer, in this calculation.

What type of transformer is used in a mobile phone charger?

Explain why core of a transformer is always laminated.

State Moseley's law

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.

Name the part of the electromagnetic spectrum which is: 
Suitable for radar systems used in aircraft navigation.

Name the part of the electromagnetic spectrum which is: 
Produced by bombarding a metal target with high electrons.

Name the electromagnetic radiation whose frequency is 10 Hz.

What is the speed of radio waves in vacuum?

Name the electromagnetic radiation that has been used in obtaining the image below.

What is the wavelength range of electromagnetic radiation used in radio broadcast?

In an atom X, electrons absorb the energy from an external source. This energy “excites” the electrons from a lower-energy level to a higher-energy level around the nucleus of the atom. When electrons return to the ground state, they emit photons.

The figure below is the energy level diagram of atom X with three energy levels, E₁ = 0.00eV, E₂ = 1.78eV and E₃ = 2.95eV. The ground state is considered 0 eV for reference. The transition of electrons takes place between levels E₁ and E₂.

1. What wavelength of radiation is needed to excite the atom to energy level E₂ from E₁?
2. Suppose the external source has a power of 100 W. What would be the rate of photon emission?

State any two difference between the primary rainbow and secondary rainbow

For any prism, prove that :

'n' or `mu = sin((A + delta_m)/2)/sin(A/2)`

where the terms have their usual meaning

Define critical angle for a given medium.

The deviation produced for violet, yellow and red lights for crown glass are 3.75°, 3.25° and 2.86° respectively. Calculate the dispersive power of the crown glass.

A ray of light is incident on a prism whose refractive index is 1.52 at an angle of 40°. If the angle of emergence is 60°, calculate the angle of the prism. 

In a regular prism, what is the relation between angle of incidence and angle of emergence when it is in the minimum deviation position?