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प्रश्न
When rays of light are incident on a glass slab then the incident ray and emergent ray are _________ each other.
- perpendicular
- parallel
- opposite
- concurrent
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उत्तर
(b) Parallel
When rays of light are incident on a glass slab, the incident and the emergent rays are parallel to each other. However, the emergent ray is displaced from the actual line of the incident ray. This is called lateral shift.
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संबंधित प्रश्न
Explain how the formation of a rainbow occurs.
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
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
A student very cautiously traces the path of a ray through a glass slab for different values of the angle of incidence (∠i). He then measures the corresponding values of the angle of refraction (∠r) and the angle of emergence (∠e) for every value of the angle of incidence. On analysing these measurements of angles, his conclusion would be
(A) ∠i > ∠r > ∠e
(B) ∠i = ∠e > ∠r
(C) ∠i < ∠r < ∠e
(D) ∠i = ∠e < ∠r
Why do we get a spectrum of seven colors when white light is dispersed by a prism?
Explain the term absolute refractive index of a medium and write an expression to relate it with the speed of light in vacuum.
State the dependence of angle of deviation On the refractive index of the material of the prism.
State the dependence of angle of deviation On the wavelength of light
A ray of light passes from water to air. How does the speed of light change?
Which colour of light travels fastest in any medium except air?
Draw the diagram of refraction of light in the glass slab
Which of the above wavelengths has a higher frequency?
How can you bend light away from the normal?
Write the relation between the angle of incidence and the angle of refraction for a medium.
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.
How does the angle of minimum deviation produces by a prism change with increase in :
the refracting angle of prism?
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)?
After tracing the path of rays of light through a glass slab for three different angles of incidence, a student measured the corresponding values angle of refraction r and angle of emergence e and recorded them in the table given below:
|
S. No. |
∠i |
∠i |
∠e |
|
I |
30° |
20° |
31° |
|
II |
40° |
25° |
40° |
|
III |
50° |
31° |
49° |
The correct observations are:
(A) I and II
(B) II and III
(C) I and III
(D) I, II and III
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 ...........
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 XX' called?
(iii) Complete the ray diagram and show the path of the incident ray PQ after passing through the lens.
(iv) The final emergent ray will either meet XX' at a point or appear to come from a point on XX'. what is the point called?
Name the phenomenon responsible in the following case:
Apparent bending of a stick in water
Why does a fisherman aim at the tail of fish during spearfishing?
Does the depth of a tank of water appear to change or remain the same when viewed normally from above?
During sunset and sunrise, the sun is seen when it is slightly below the horizon. Give reason.
State the factors on which the angle of deviation depends.
Can the absolute refractive index of a medium be less than one?
Draw a diagram to show the refraction of a monochromatic light ray through an equilateral prism. On the diagram, label the incident, refracted, and emergent rays. It also indicates the angle of deviation by the letter δ.
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?
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?
The velocity of light in diamond is 121000 kms-1. What is its refractive index?
