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

If magnetic susceptibility of a certain magnetic material is 0 0001, find its relative permeability.

Half-life of a certain radioactive material is 8 hours.

Find the disintegration constant of this material.

Half life of a certain radioactive material is 8 hours.
If one starts with 600 g of this substance, how much of it will disintegrate in one day? 

The first line of Balmer series (H_α) in the spectrum of hydrogen is obtained when an electron of hydrogen atom goes from ______.

What is the geometrical shape of the wavefront for:

1. Light diverging from a point source?
2. The pattern of wavefront of the light from a distant star intercepted by earth?

What is the phase difference between any two points lying on the same?

Explain the following term:

Drift velocity and Mobility

On what factor does the maximum kinetic energy of the photoelectrons in a photo cell depend?

If the radius of second electron orbit in hydrogen atom be r then the radius of the third orbit will be ______.

Distinguish between the forces experienced by a moving charge in a uniform electric field and in a uniform magnetic field. (Any two points)

What type of wavefronts are associated with a source infinity?

Calculate electric potential at a point P which is at a distance of 9 cm from a point charge of 50 μC.

When an electric current is passed through a wire or a coil, a magnetic field is produced. Is the reverse phenomenon possible i.e, can a magnetic field produce an electric current? Explain with the help of an appropriate example.

A long straight wire AB carries a current of 5A. P is a proton travelling with a velocity of 2 × 10⁶ m/s, parallel to the wire, 0.2 m from it and in a direction opposite to the current, as shown in Figure below. Calculate the force which magnetic field of the current carrying conductor AB exerts on the proton.

Using Huygen's wave theory of light, show that the angle of incidence is equal to the angle of reflection. Draw a neat and labelled diagram.

Lorentz force in vector form is ______.

What type of wavefronts are associated with a point source of light?

A 220V, 50Hz ac source is connected to a coil having coefficient of self-induction of 1H and a resistance of 400 Ω. Calculate:

1. the reactance of the coil.
2. the impedance of the coil.
3. the current flowing through the coil.

State any one difference between a direct current (dc) and an alternating current (ac).

Radius of the 1^st orbit of hydrogen atom is r₀. What will be the radius of the 4^th orbit?