English

Can the absolute refractive index of a medium be less than one?

Advertisements
Advertisements

Questions

Can the absolute refractive index of a medium be less than one?

Can the value of the absolute refractive index be lesser than 1?

Very Short Answer
Advertisements

Solution

No, the absolute refractive index of a medium cannot be less than one because the speed of light in any medium is always less than that in a vacuum.

shaalaa.com
  Is there an error in this question or solution?

RELATED QUESTIONS

When a ray of light travels from air to glass slab and strikes the surface of separation at 90°, then it …………….
(a) bends towards normal
(b) bends away from normal
(c) passes unbent
(d) passes in zigzag way


Explain how the formation of a rainbow occurs.


On the basis of the experiment, "To trace the path of a ray of light through a rectangular glass slab", students of a class arrived at which one of the following conclusions?

(A) Angle of incidence is greater than the angle of emergence.

(B) Angle of emergence is smaller than the angle of refraction.

(C) Emergent ray is parallel to the refracted ray.

(D) Incident ray and emergent ray are parallel to each other.


Draw diagrams to show the refraction of light from 

  1. air to glass, and
  2. glass to air. In each diagram, label the incident ray, refracted ray, the angle of incidence
  3. and the angle of refraction (r).

In the adjacent diagram, AO is a ray of light incident on a rectangular glass slab.

  1. Complete the path of the ray till it emerges out of the slab.
  2. 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?
  3. Mark angles of emergence by the letter e. How are the angles i and e related?
  4. Which two rays are parallel to each other? Name them.
  5. Indicate in the diagram the lateral displacement between the emergent ray and the incident ray. State one factor that affects the lateral displacement.

A ray of light is passing from a transparent medium 1 to another transparent medium 2 (i) Speed up (ii) slows down. In each case, state whether the refractive index of medium 2 is equal to, less than or greater than the refractive index of medium 1. 


The critical angle for glass-air is 45° for the light of yellow colour. State whether it will be less than, equal to, or more than 45° for (i) ref light, (ii) blue light? 


A total reflecting right angled isosceles prism can be used to deviate a ray of light through:
(a) 30° (b) 60° (c) 75° (d) 90°. 


Select from the following the best set-up for tracing the path of a ray of light through a rectangular glass slab: 


(A) I

(B) II

(C) III

(D) IV


Four students A, B, C and D traced the paths of incident ray and the emergent ray by fixing pins P and Q for incident ray and pins R and S for emergent ray for a ray of light passing through a glass slab.

The correct emergent ray was traced by the student: 

(1) A

(2) B

(3) C

(4) D


(i) What is the relation between the refractive index of water with respect to air `("_aμ_\text(w))` and the refractive index of air with respect to water `("_\text(w)μ_ a)` .
(ii) If the refractive index of water with respect to air `("_aμ_\text(w))` is`5/3`. Calculate the refractive index of air with respect to water `("_\text(w)μ_ a)` . 


Write the SI unit for refractive index.

Which of the following has the highest refractive index:


Why does the sun appear bigger during sunset or sunrise?


What is the total reflecting prism?


After a robbery, if a window has been broken, there will be tiny particles of glass. Some of these will be found at the scene of the crime and some may be caught in the thief’s clothing. If the police can prove that these particles are identical, they have a strong case.
A method of doing this is to suspend the particles of glass in a special liquid. Light of a single colour is thrown through the liquid and the particles viewed through a microscope. The temperature of the liquid is then slowly altered. This alters the speed of light through the liquid (i.e., it alters the refractive index). At one particular temperature, the particles of glass disappear. It this happens at the same temperature for both sets of glass particles, they probably came from the same broken pane of glass.
Complete and copy the diagram to show how light bends when it travels from the liquid to the glass and back to the liquid, If the light slows down in the glass.


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.


How will you verify the laws of refraction or how the refractive index of glass is determined in the laboratory?


Calculate the velocity of light in a glass block of refractive index 1.5. (Velocity of light in air = 3 × 10m/s)


The speed of light in air is 3 × 10ms-1. Calculate the speed of light in water. The refractive index of water is 4/3.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×