Class 7 Science
NCERT Solution Part 2
Question 8: Give one use each of a concave and a convex mirror.
Answer: (a) Concave mirror is used in solar furnace.
(b) Convex mirror is used in rear view mirrors.
Question 9: Which type of mirror can form a real image?
Answer: Concave mirror
Question 10: Which type of lens forms always a virtual image?
Answer: Concave lens
Choose the correct option in questions 11–13
Question 11: A virtual image larger than the object can be produced by a
- Concave lens
- Concave mirror
- Convex mirror
- Plane mirror
Answer: (c) Concave mirror
Question 12: David 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, then the distance between David and his image will be
Answer: (a) 3 m
Question 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
Answer: (b) 2 m/s