Advertisements
Advertisements
Question
Explain how to read the following message which was found on some blotting paper:
Advertisements
Solution
Place a plane mirror in front of the message and see the image of the message. The mirror now reads Meet me at midnight. The phenomenon of lateral inversion is used here.
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 |
Name the phenomenon responsible for the following effect:
When we sit in front of a plane mirror and write with our right hand, it appears in the mirror that we are writing with the left hand.
The letter F is placed in front of a plane mirror:
- How would its image look like when seen in a plane mirror?
- What is the name of the phenomenon involved?
A wall reflects light and a mirror also reflects light. What difference is three in the way they reflect light?
The boy walks towards the mirror at a speed of 1 m/s. At what speed does his image approach him?
Define the following terms used in the study of reflection of light by drawing a labelled ray-diagram:
- Incident ray
- Point of incidence
- Normal
- Reflected ray
- Angle of incidence
- Angle of reflection
State and explain the laws of reflection of light at a plane surface (like a plane mirror), With the help of a labelled ray-diagram. Mark the angles of 'incidence' and 'reflection' clearly on the diagram. If the angle of reflection is 47.5°, what will be the angle of incidence?
In which material do you think light rays travel faster-glass or air?
A vertical ray of light strikes the horizontal surface of some water:
- What is the angle of incidence?
- What is the angle of refraction?
Air is optically .......... than glass.
A light ray suffers reflection and refraction at the boundary in passing from air to water. Draw a neat labelled ray diagram to show it.
Define the principal focus of a concave mirror.
Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass? The speed of light in vacuum is 3 × 108 m s−1.
A real image is formed by the light rays after reflection or refraction when they:
- actually meet or intersect with each other.
- actually converge at a point.
- appear to meet when they are produced in the backward direction.
- appear to diverge from a point.
Which of the above statements are correct?
The refractive index of four substances A, B, C, and D are 1.31, 1.43, 1.33, 2.4 respectively. The speed of light is maximum in
Assertion and reasoning type
- Assertion: If the refractive index of the medium is high (denser medium) the velocity of the light in that medium will be small
- Reason: Refractive index of the medium is inversely proportional to the velocity of the light
The angle of incidence for a ray of light having zero reflection angle is ______.
Why a pencil partly immersed in water appears to be bent at the water surface.
When a ray of light travels normal to the given surface, then the angle of refraction is ______.
