Advertisements
Advertisements
Question
The diagram alongside shows the refraction of a ray of light from air to a liquid.
- Write the values of (i) angle of incidence, (ii) angle of refraction.
- Use Snell’s law to find the refractive index of liquid with respect to air.

Advertisements
Solution
(a) (i) Angle of incidence is the angle which the incident ray makes with normal.
∠i = 90° - 30° = 60°
(ii) The angle that the refracted beam creates with the normal is known as the angle of refraction.
∠r = 90° - 45° = 45°
(b) liquid's refractive index in relation to air.
μ Liquid = `sin i/sin r`
= `(sin 60°)/(sin 45°)`
= `(sqrt3/2)/(1/sqrt2)`
= `sqrt3/2 xx sqrt2`
= `(sqrt3 xx sqrt2)/(sqrt2 xx sqrt2)`
= `sqrt(3/2)`
APPEARS IN
RELATED QUESTIONS
When rays of light are incident on a glass slab then the incident ray and emergent ray are _________ each other.
- perpendicular
- parallel
- opposite
- concurrent
State the dependence of angle of deviation On the wavelength of light
Light passes through a rectangular glass slab and through a triangular glass prism. In what way does the direction of the two emergent beams differ and why?
Draw the diagram of refraction of light in the glass slab
The refractive index of air with respect to glass is expressed as `""_g μ_a=sin i /sin r`.
- Write down a similar expression for aμg in terms of the angles i and r.
- If angle r = 90°, what is the corresponding angle i called?
- What is the physical significance of the angle i in part (b)?
Rahim recorded the following sets of observations while tracing the path of a ray of light passing through a rectangular glass slab for different angles of incidence.
|
S. No. |
Angle of incidence |
Angle of refraction |
Angle of emergence |
|
I |
45° |
41° |
45° |
|
II |
40° |
38° |
38° |
|
III |
45° |
41° |
40° |
|
IV |
41° |
45° |
41° |
The correct observation is recorded at serial number:
(1) I
(2) II
(3) III
(4) IV
Fill in the blank to complete the following sentence:
When light travels from a rarer to a denser medium, it bends ...........
Does the depth of a tank of water appear to change or remain the same when viewed normally from above?
Can the absolute refractive index of a medium be less than one?
The diagram shows the path of a ray of light through a rectangular glass block placed in a liquid of uniform density.

What is the angular, deviation of the emergent ray from the glass block with respect to the incident ray?
