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प्रश्न
Can the absolute refractive index of a medium be less than one?
Can the value of the absolute refractive index be lesser than 1?
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उत्तर
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.
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संबंधित प्रश्न
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
Select from the following the best experimental setup for tracing the path of a ray of light passing through a rectangular glass slab.
(a) P
(b) Q
(c) R
(d) S
Four students P, Q, R and S traced the path of a ray of light passing through a glass slab for an angle of incidence 40° and measured the angle of refraction. The values as measured them were 18°; 22°; 25° and 30° respectively. The student who has performed the experiment methodically is
(A) P
(B) Q
(C) R
(D) S
Name one factor that affects the lateral displacement of light as it passes through a rectangular glass slab.
Which of the above wavelengths has a higher frequency?
A ray of light passes from glass into air. The angle of refraction will be:
(a) equal to the angle of incidence
(b) greater than the angle of incidence
(c) smaller than the angle of incidence
(d) 45°
How does the angle of minimum deviation produces by a prism change with increase in :
the wavelength of incident light
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.
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.
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?
Choose the correct alternative and rewrite the following:
A glass slab is placed in the path of convergent light. The point of convergence of light
Name the phenomenon responsible in the following case:
Apparent bending of a stick in water
During sunset and sunrise, the sun is seen when it is slightly below the horizon. Give reason.
What is the refractive index of vacuum
How does the angle of deviation produced by a prism depend on the colour of light used? Which colour of white light is deviated (i) most, (ii) least, by a prism?
How does the angle of deviation produced by a prism depend on the angle of incidence of light at the prism surface? Draw a graph to illustrate your answer.
