Advertisements
Advertisements
प्रश्न
Define the absolute refractive index.
Define absolute refractive index of an optical medium.
Advertisements
उत्तर
APPEARS IN
संबंधित प्रश्न
A student traces the path of a ray of light passing through a rectangular glass slab and marks the angle of incidence i, angle of refraction r and angle of emergence e, as shown.

The correctly marked angle(s) is/are
(A) ∠ i only
(B) ∠ e only
(C) ∠ r only
(D) ∠ i and ∠ e
Name one factor that affects the lateral displacement of light as it passes through a rectangular glass slab.
The speed of light in glass is 2 × 105 km/s. What is the refractive index of glass?
How is the refractive index of a medium related to the speed of light in it?
A monochromatic ray of light passes from air to glass. The wavelength of light in air is λ, the speed of light in air is c and in glass is V. If the absolute refractive index of glass is 1.5, write down
- the relationship between c and V,
- the wavelength of light in glass.
A ray of light enters a glass slab ABDC as shown in figure and strikes at the centre O of the circular part AC of the slab. The critical angle of glass is 42°. Complete the path of the ray till it emerges out from the slab. Mark the angles in the diagram wherever necessary.

“A ray of light incident on a rectangular glass slab immersed in any medium emerges parallel to itself.” Draw labelled ray diagram to justify the statement.
What is the correct reason for blinking / flickering of stars? Explain it.
a) The blasts in the stars.
b) Absorption of star light by the atmosphere.
c) Motion of the stars.
d) Changing refractive index of gases in the atmosphere.
Fill in the blank to complete the following sentence:
When light travels from a rarer to a denser medium, it bends ...........
In the fig., PO is a ray of light incident on a rectangular glass block.
(a) Complete the path of the ray through the block.
(b) In the diagram, mark the angle of incidence (i) and the angle of refraction (r) at the first interface. How is the refractive index of glass related to the angles I and r?
(c) Mark angle of emergence by the letter e. How are the angles i and e related?
(d) Which two rays are parallel to each other? Name them.
(e) Indicate in the diagram the lateral displacement between the emergent ray and the incident ray.

Fig shows a lens as a combination of a glass block and two prisms.
(i) Name the lens formed by the combination.
(ii) What is the line XX' called?
(iii) Complete the path of the incident ray PQ after passing through the lens.
(iv) The final emergent ray either meets XX' at a point or appears to come from a point on XX'. Label it as F, What is this point called?
A ray of light strikes the surface at a rectangular glass slab such that the angle of incidence is 45o.
In each case, draw diagram to show the path taken by the ray as it passes through the glass slab and emerges from it.
Why upper surface of water contained in a beaker and above eye level appears silvery?
In the diagram alongside a ray of light, PQ is incident normally on one face AB of an equilateral glass prism. What is the angle of incidence at the faces AB and AC?

A ray of monochromatic light is incident from the air on a glass slab:
(i) Draw a labelled ray diagram showing the change in the path of the ray till it emerges from the glass slab.
(ii) Name the two rays that are parallel to each other.
(iii) Mark the lateral displacement in your diagram.
Which colour of white light travels fastest in any medium except air?
