Ans. (a)(v); (b) (ii); (c) (i); (d) (iii); (e) (vi).
Q.4 State the characteristics of the image formed by a plane mirror.
Ans. The characteristics of the image formed by a plane mirror are:
(i) It forms and erect image.
(ii) It forms a virtual image.
(iii) It forms the image behind the mirror.
(iv) The size of the image is same as that of the object.
(v) It forms the image at the same distance behind the mirror as the object stands infront of it.
Q.5 Find out the letters of English alphabet or any other language known to you in which the image formed in a plane mirror appears exactly like the letter itself. Discuss your findings.
Ans. Letters like A, H, I, M, O, T, U, Vnand W.
Q.6 What is a virtual image? Give one situation where a virtual image is formed.
Ans. The image which cannot be taken on a screen is called a virtual image.
For example, when an object is placed very close to the concave mirror, we do not get any image of that object on the white screen placed behind the mirror. This type of image is known as virtual image.
Q.7 State two differences between a convex and a concave lens.
(i) These are thick at the middle and thin at the edge.
(ii) They can form magnified image.
(i) These are thin at the middle and thick at the edge.
(ii) The image formed by these lens are always diminished in size.
Q.8 Give one use each of a concave and a convex mirror.
Ans. Use of Concave Mirror: It is used by dentists to examine the teeth.
Use of Convex Mirror: It is used in vehicles as rear view mirror.
Q.9 Which type of mirror can form a real image?
Ans. Concave mirror.
Q.10 Which type of lens forms always a virtual image?
Ans. Concave lens.
Choose the correct option: (11-13)
Q.11 A virtual image larger than the object can be produced by a:
(i) concave lens (ii) concave mirror
(iii) convex mirror (iv) plane mirror.
Q.12 David is observing his image in a plane mirror. The distance between the mirror and his image is 4m. If he moves 1 m towards the mirror, then the distance between David and his image will be:
(i) 3m (ii) 5m (iii) 6m (iv) 8m.
Q.13 The rear view mirror of a car is a plane mirror. A driver is reversing his car at a speed of 2 m/s. The driver sees in his rear view mirror the image of a truck parked behind his car. The speed at which the image of the truck appears to approach the driver will be:
(i) 1 m/s (ii) 2 m/s (iii) 4 m/s (iv) 8 m/s.
Ans. 11. (ii) concave mirror; 12. (iii) 6m; 13.(iii) 4m/s.