Advertisements
Advertisements
Question
Trace a ray of light incident at 30° on a surface if travelling from air to glass. What is the angle of refraction in this case? (R.I. for glass = 3/2).
Advertisements
Solution
aμg = `sin"i"/sin"r"`
∴ `3/2=(sin30°)/sin"r"`
∴ Sin r = `2/3xxsin30°`
But sin 30° = `1/2`
∴ sin r = `2/3xx1/2`
= `1/3`
∴ sin r = 0.3334
∴ sin r = 19°30′.
Angle of refraction for air to glass = 19°30′.
RELATED QUESTIONS
After tracing the path of a ray of light passing through a rectangular glass slab for four different values of the angle of incidence, a student reported his observations in tabular form as given below:
| S.No | ∠ i | ∠ r | ∠ e |
| I | 30° | 19° | 29° |
| II | 40° | 28° | 40° |
| III | 50° | 36° | 50° |
| IV | 60° | 40° | 59° |
The best observation is
(A) I
(B) II
(C) III
(D) IV
Why do we get a spectrum of seven colors when white light is dispersed by a prism?
Draw the diagram of refraction of light in the glass slab
Four students showed the following traces of the path of a ray of light passing through a rectangular glass slab.
The trace most likely to be correct is that of student
(A) I
(B) II
(C) III
(D) IV
Why is the colour red used as a sign of danger?
The refractive index of air with respect to glass is defined: as gµa = sin i/sin r
Write down a similar expression for aµg in terms of angle i and r.
Draw ray of light bending towards the normal while passing from air to glass. Label your diagrams.
How will you verify the laws of refraction or how the refractive index of glass is determined in the laboratory?
The speed of light in air is 3 × 108 ms-1. Calculate the speed of light in water. The refractive index of water is 4/3.
