Answer in short.
1. What is reflection of light How does it help us?
2. Explain a mirror and its classification
3. What happens when the incident ray strikes the reflecting surface normally?
4. What are the factors on which the reflection of light from any surface depends?
5. Draw a well-labelled diagram to explain image formation of a large object by a plane mirror.
6. Find out letters in English alphabets which resemble their image formed by a plane mirror.
7. What is a virtual image? Give one situation in which virtual image is formed.
8. Rohan is observing his image in a plane mirror. The distance between the mirror and his image is
4 m. If he moves 1 m towards the mirror, find the distance between the image and the mirror?
9. Name the three primary colours.
Answers
Answer:
(1) Rays of light reflect, or bounce off, objects just like a ball bounces on the ground. This reflection of light is what enables us to see everything around us. Take a look out your window: you see everything in the natural world (that doesn't produce its own light) because it reflects the light of the Sun .
(2) A mirror is a smooth surface on which regular reflection takes place. A clear image of an object placed in front of a mirror is formed due to reflection of light. Plane mirror: If the reflecting surface is plane and smooth and regular reflection of light takes place on it, then this surface is called plane mirror.
(3) Answer. For a plane mirror: If the incident ray falls along the normal, the angle of incidence is 0 degrees, NOT 90 degrees. The angle is measured with the normal to the mirror and not with the plane of the mirror. Hence the angle of reflection is equal to 0 degrees
(4) Explanation: The amount of light reflected by an object, and how it is reflected, is highly dependent upon the degree of smoothness or texture of the surface. When surface imperfections are smaller than the wavelength of the incident light (as in the case of a mirror), virtually all of the light is reflected equally.
(6) If the letters of English alphabet A, H, I, M, O, T, U, V, W, X, Y are kept in front of a plane mirror, then they would form images which exactly look like the original letters of the alphabet. These letters are vertically symmetric.
(7) Give one situation where a virtual image is formed. Answer: The image which cannot be obtained on a screen is called virtual image. For example, virtual image is always formed in case of plane mirror and convex mirror. Question 7: State two differences between a convex and a concave lens.
(9) Color Basics
Three Primary Colors (Ps): Red, Yellow, Blue.
Three Secondary Colors (S'): Orange, Green, Violet.
Six Tertiary Colors (Ts): Red-Orange, Yellow-Orange, Yellow-Green, Blue-Green, Blue-Violet, Red-Violet, which are formed by mixing a primary with a secondary.
Answer:
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