Advertisements
Advertisements
Question
Write scientific reason.
The sun appears on the western horizon for some time after sunset.
Advertisements
Solution
- As ray of light from the Sun enters the earth’s atmosphere, it follows a curved path due to refraction, before reaching the observer.
- This makes the apparent position of the Sun slightly higher than the actual position for the observer.
- Hence, due to the atmospheric refraction of sunlight, the observer on the earth continues to see the setting Sun for two minutes after the Sun has dipped below the horizon, thus delaying the sunset.
APPEARS IN
RELATED QUESTIONS
| 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 |
Which property of light makes a pencil cast a shadow when it is held in front of a light source?
Fill in the following blank with a suitable word:
When light is reflected, the angles of incidence and reflection are ............ .
State whether the following statement is true of false:
A student says that we can see an object because light from our eyes is reflected back by the object.
Where is the image when you look at something in a mirror?
The letter F is placed in front of a plane mirror:
How would its image look like when seen in a plane mirror?
Write the word AMBULANCE as it would appear when reflected in a plane mirror. Why is it sometimes written in this way (as its mirror image) on the front of an ambulance?
Which type of reflection of light leads to the formation of images?
The boy walks towards the mirror at a speed of 1 m/s. At what speed does his image approach him?
The angle of reflection is equal to the angle of incidence:
(a) always
(b) sometimes
(c) under special conditions
(d) never
A man stands 10 m in front of a large plane mirror. How far must the walk before he is 5 m away from his image?
An object is placed 20 cm in front of a plane mirror. The mirror is moved 2 cm towards the object. The distance between the positions of the positions of the original and final images seen in the mirror is ______.
A ray of light travelling in glass emerges into air. State whether it will bend towards the normal or away from the normal.
A ray of light goes from water into air. Will it bend towards the normal or away from the normal?
Which phenomenon of light makes the water to appear shallower than it really is?
What is meant by the 'angle of incidence' and the 'angle of refraction' for a ray of light?
Light travels more quickly through water than through glass.
Which is optically denser : water or glass?
A ray of light passes from a medium X to another medium Y. No refraction of light occurs if the ray of light hits the boundary of medium Y at an angle of:
(a) 0°
(b) 45°
(c) 90°
(d) 120°
A vertical ray of light strikes the horizontal surface of some water:
What is the angle of refraction?
A ray of light when passes from glass to air, bends towards the normal.
Light travels at a lower speed in water than in air.
When a ray of light travels from air to glass, it bends .......... the normal.
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.
Observe the given figure and name the following.
| Ray AB | |
| Ray NM | |
| Ray MD | |
| ∠ r |
State whether true or false. If false, correct the statement.
The angle of deviation depends on the refractive index of the glass.
Why does a ray of light bend when it travels from one medium to another?
The refractive index of a transparent medium is always greater than ______.
What is refractive index?
You are given water, mustard oil, glycerine and kerosene. In which of these media a ray of light incident obliquely at same angle would bend the most?
If a beam of red light and a beam of violet light are incident at the same angle on the inclined surface of a prism from air medium and produce angles of refraction r and v respectively, which of the following is correct?
The angle of incidence from air to glass at the point O on the hemispherical glass slab is.
When light passes from one medium to another the ray gets bent. This property of light is called ______.
The bending of light as it passes from one medium to another is called ______.
A star appears twinkling into the sky because of the reflection of light by the atmosphere.
A water tank appears shallower when it is viewed from the top due to refraction.
Assertion: The air bubble shines in water.
Reason: Air bubble shines due to the refraction of light.
