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प्रश्न
What is a spectrum?
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उत्तर
The band of colored components of a beam of light is called a spectrum.
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संबंधित प्रश्न
Write a short note on dispersion of light.
Why do we get a spectrum of seven colors when white light is dispersed by a prism?
State the dependence of angle of deviation On the refractive index of the material of the prism.
The speed of light in glass is 2 × 105 km/s. What is the refractive index of glass?
A ray of light passes from water to air. How does the speed of light change?
Why is the ratio of the velocities of light of wavelengths 4000Å and 8000Å in vacuum 1: 1?
For which colour of white light, is the refractive index of a transparent medium the most?
When a ray of light from air enters a denser medium, it ______.
How does the angle of deviation produced by a prism change with increase in the angle of incidence. Draw a curve showing the variation in the angle of deviation with the angle of incidence at a prism surface.
An object is viewed through a glass prism with its vertex pointing upwards. It appears to be displaced upward. Explain the reason.
A Water pond appears to be 2.7 m deep. If the refractive index of water is 4/3, find the actual depth of the pond.
What is meant by the statement the critical angle for diamond is 24°?
A ray of light falls normally on the surface of a transparent glass slab. Draw a ray diagram to show its path and also mark angle of incidence and angle of emergence.
A student traces the path of a ray of white light through a rectangular glass slab and marks, the angles of incidence (∠i) , refraction (∠r) and emergence (∠e) as shown. Which angle or angles has he not marked correctly?
(A) ∠i only
(B) ∠i and ∠r
(C) ∠i and ∠e
(D) ∠r and ∠e
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.
(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)` .
Which of the following has the highest refractive index:
In the fig., PO is a ray of light incident on a rectangular glass block.
(a) Complete the path of the ray through the block.
(b) 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?
(c) Mark angle of emergence by the letter e. How are the angles i and e related?
(d) Which two rays are parallel to each other? Name them.
(e) Indicate in the diagram the lateral displacement between the emergent ray and the incident ray.
Fig. shows a ray of white light that passes through a prism and produces a spectrum.
(a) Name the phenomenon that is taking place.
(b) What colour would you see at X and Y?
(c) What radiation would you detect above X and below Y?
Which colour of light travels fastest in any medium except air?
How does the deviation produced by a prism depend on the refraction index of its material.
The critical angle for glass-air interface is :
A ray of light passes from water to air. How does the speed of light change?
Why is the colour red used as a sign of danger?
During sunset and sunrise, the sun is seen when it is slightly below the horizon. Give reason.
How is the refractive index of a medium related to its real depth and apparent depth?
Name two instruments of the total refracting prism in which is used.
Draw ray of light bending towards the normal while passing from glass to water. Label your diagrams.
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?
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).
Trace a ray of light incident at 30° on a surface if travelling from glass to air. What is the angle of refraction in this case? (R.I. for glass = 3/2).
Calculate the velocity of light in a glass block of refractive index 1.5. (Velocity of light in air = 3 × 108 m/s)
A ray of light PQ is incident normally on the hypotenuse of a right-angled prism ABC as shown in the diagram given below:
(i) Copy the diagram and complete the path of the ray PQ till it emerges from the prism.
(ii) What is the value of the angle of deviation of the ray?
(iii) Name an instrument where this action of the prism is used.
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.
The refractive index of glass with respect to air is 1.5. What is the value of the refractive index of air with respect to glass?
A ray of light is incident at an angle of 45° on one face of a rectangular glass slab of thickness 10 cm and refractive index 3/2. Calculate the lateral shift produced ______.
Draw the ray diagram of a glass slab having medium A and B for the velocity of light ray VA and VB respectively and define Snell's law.
- If VB = 1.5 VA, then which medium is denser?
- What is the refractive index of A with respect to B?
- What is the refractive index of B with respect to A?
