Science (English Medium) Class 12 - CBSE Question Bank Solutions for Physics

A rectangular block of glass ABCD has a refractive index 1.6. A pin is placed midway on the face AB (Figure). When observed from the face AD, the pin shall ______.

1. appear to be near A.
2. appear to be near D.
3. appear to be at the centre of AD.
4. not be seen at all.

A jar of height h is filled with a transparent liquid of refractive index µ (Figure). At the centre of the jar on the bottom surface is a dot. Find the minimum diameter of a disc, such that when placed on the top surface symmetrically about the centre, the dot is invisible.

In a Young’s double slit experiment, the source is white light. One of the holes is covered by a red filter and another by a blue filter. In this case ______.

Why is the diffraction of sound waves more evident in daily experience than that of light wave?

Consider a two-slit interference arrangement (Figure) such that the distance of the screen from the slits is half the distance between the slits. Obtain the value of D in terms of λ such that the first minima on the screen falls at a distance D from the centre O.

Two H atoms in the ground state collide inelastically. The maximum amount by which their combined kinetic energy is reduced is ______.

In a Young’s double slit experiment, the path difference at a certain point on the screen between two interfering waves is `1/8`th of the wavelength. The ratio of intensity at this point to that at the centre of a bright fringe is close to ______.

ASSERTION (A): In an interference pattern observed in Young's double slit experiment, if the separation (d) between coherent sources as well as the distance (D) of the screen from the coherent sources both are reduced to 1/3^rd, then new fringe width remains the same.

REASON (R): Fringe width is proportional to (d/D).

A slit of width 0.6 mm is illuminated by a beam of light consisting of two wavelengths 600 nm and 480 nm. The diffraction pattern is observed on a screen 1.0 m from the slit. Find:

1. The distance of the second bright fringe from the central maximum pertaining to the light of 600 nm.
2. The least distance from the central maximum at which bright fringes due to both wavelengths coincide.

A ray of light passes through a prism of refractive index `sqrt2` as shown in the figure. Find:

1. The angle of incidence (∠r₂) at face AC.
2. The angle of minimum deviation for this prism.

How will the interference pattern in Young's double-slit experiment be affected if the screen is moved away from the plane of the slits?

How will the interference pattern in Young's double-slit experiment be affected if the source slit is moved away from the plane of the slits?

How will the interference pattern in Young's double-slit experiment be affected if the phase difference between the light waves emanating from the two slits S₁ and S₂ changes from 0 to π and remains constant?

In Young's double slit experiment using light of wavelength 600 nm, the slit separation is 0.8 mm and the screen is kept 1.6 m from the plane of the slits. Calculate

1. the fringe width
2. the distance of (a) third minimum and (b) fifth maximum, from the central maximum.

A beam of light consisting of two wavelengths 600 nm and 500 nm is used in Young's double slit experiment. The silt separation is 1.0 mm and the screen is kept 0.60 m away from the plane of the slits. Calculate:

1. the distance of the second bright fringe from the central maximum for wavelength 500 nm, and
2. the least distance from the central maximum where the bright fringes due to both wavelengths coincide.

The formation of the depletion region in a p-n junction diode is due to ______.

• Assertion (A): In Young's double slit experiment all fringes are of equal width.
• Reason (R): The fringe width depends upon the wavelength of light (λ) used, the distance of the screen from the plane of slits (D) and slits separation (d).

In Young's double-slit experiment, the separation between the two slits is d and the distance of the screen from the slits is 1000 d. If the first minima fall at a distance d from the central maximum, obtain the relation between d and λ.

In Young's double-slit experiment, the screen is moved away from the plane of the slits. What will be its effect on the following?

1. The angular separation of the fringes.
2. Fringe-width.

During the formation of a p-n junction ______.