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प्रश्न
A ray of light strikes a plane mirror PQ at an angle of incidence of 30°, is reflected from the plane mirror and then strikes a second plane mirror QR placed at right angles to the first mirror. The angle of reflection at the second mirror is ______.
विकल्प
30°
45°
60°
90°
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उत्तर
A ray of light strikes a plane mirror PQ at an angle of incidence of 30°, is reflected from the plane mirror and then strikes a second plane mirror QR placed at right angles to the first mirror. The angle of reflection at the second mirror is 60°.
APPEARS IN
संबंधित प्रश्न
| Column I | Column II | Column III | |
| 1 | Dispersion | Long-sightedness | Twinkling of stars |
| 2 | Refraction | Splitting of white light into component colours | Convex lens |
| 3 | Hypermetropia | Change in the direction of the ray of light due to change in medium | Spectrum of seven colours |
Name the phenomenon responsible for the following effect:
When we sit in front of a plane mirror and write with our right hand, if appears in the mirror that we are writing with the left hand.
What is the difference between regular reflection of light and diffuse reflection of light?
A boy with a mouth 5 cm wide stands 2 m away from a plane mirror. Where is his image and how wide is the image of his mouth?
Write all the capital letters of the alphabet which look the same in a plane mirror.
The angle of reflection is equal to the angle of incidence:
(a) always
(b) sometimes
(c) under special conditions
(d) never
Which phenomenon of light makes the water to appear shallower than it really is?
State whether the following statement is true or false:
Refraction occurs because light slows down in denser materials.
Fill in the following blank with suitable word:
Light bends when is passes from water into air. We say that it is ............
With the help of a diagram, show how when light falls obliquely on the side of a rectangular glass slab, the emergent ray is parallel to the incident ray.
A ray of light when passes from glass to air, bends towards the normal.
The diagram (figure) given below shows two parallel rays 1 and 2 incident on (a) a concave mirror, (b) a convex mirror. Draw the reflected rays and mark the focus by the symbol F.

A ray of light passes from medium 1 to medium 2. Which of the following quantities of the refracted ray will differ from that of the incident ray: Speed, intensity, frequency, wavelength?
A small air bubble in a glass block when seen from above appears to be raised because of ______.
Lights of different colours are used as signal for safety transport. From these, the wavelength of red light is _______ nm.
Noor, a young student, was trying to demonstrate some properties of light in her Science project work. She kept ‘X’ inside the box (as shown in the figure) and with the help of a laser pointer made light rays pass through the holes on one side of the box. She had a small butter-paper screen to see the spots of light being cast as they emerged.

Her friend noted the following observations from this demonstration:
- Glass is optically rarer than air.
- Air and glass allow light to pass through them with the same velocity.
- Air is optically rarer than glass.
- Speed of light through a denser medium is faster than that of a rarer medium.
- The ratio: sin of angle of incidence in the first medium to the ratio of sin of angle of refraction in the second medium, gives the refractive index of the second material with respect to the first one.
Which one of the combinations of the above statements given below is correct.
Which is optically denser out of the two medium M1& M2 having the refractive indices = 1.71 and 1.36 respectively?
The bottom of swimming pool appears to be less deep than the actual one because of
