6. The image of an extended object placed in front of a concave mirror is formed at a distance of 40 cm from the object. If the image is 3 times bigger than the object, the magnitude of focal length of the mirror is a) 5 cm b) 10 cm c) 20 cm d) 15 cm 7. What is not a characteristic of a rearview mirror in a car? a) They give a virtual image b) Convex in nature d) They have wider field of coverage 8. 9. c) Concave in nature Which of the following lenses would you prefer to use while reading small letters found in a dictionary? a) A convex lens of focal length 50 cm c) A concave lens of focal length 50 cm b) A convex lens of focal length 5 cm d) A concave lens of focal length 5 cm A piece of red cloth when suitably illuminated may look black, but a piece of black cloth will never appear red. This phenomenon occurs because: a) Red cloth reflects all colours c) Black cloth reflects only black light b) Black cloth reflects all colours d) Black absorbs all the colours 10. A man is standing at a position X in front of a plane mirror, a distance of y metre from the mirror as shown in figure. When the man moves 5 m away from the mirror, the new distance between the man and his image becomes 20 metre. What is the value of y? (metre) a) 5 m c) 10 m 5 m b) 40 m d) 20 m