Optics - Test Questions (Objective type Questions)

1. A convex mirror forms image of a real object . Th image will be
(a) real, erect                  (b) real,inverted
(c) virtual, erect              (d) virtual, inverted

2. In case of spherical mirrors, the focal length and the radius of curvature are related as-
(a)  f = R/2                 (b) f = 2R
(c)  f = R                    (d) None of these

3. A dentist's concave mirror has a focal length of 3 cm. The mirror is placed 2 m from the tooth. The magnification of the image will be
(a)  +6                      (b) +1/6
(c)  -3                       (d) +3

4. In search lights and head lights of automobiles the mirror used is
(a) Concave mirror          (b) Plane mirror
(c) Convex mirror           (d) None of these

5. A ray of light is incident on a plane mirror at an angle of incidence 30°.The ray after reflection is deviated through
(a) 30°                            (b) 60°
(c) 90°                            (d) 120°

6. A virtual image larger than the object can be produced by
(a) A concave mirror      (b) A convex mirror
(c) A plane mirror           (d) Concave  lens

7. A diminished virtual image can be obtained only in the
(a) Concave spherical mirror      (b)  Plane mirror 
(c) Convex spherical mirror       (d)  Concave Parabolic mirror

8. Reflectors used in solar cookers are
(a)  Plane                 (b) Concave
(c) Convex              (d) Cylinderical

9. Which of the following mirrors is also known as shaving mirror
(a) Concave           (b) Convex 
(c)  Plane               (d) None of these

10. Light waves have 
(a) Particle nature    (b) Wave nature
(c) Dual nature        (d) none of these

11.which of the following mirror cannot form a virtual image ?
(a) Concave      (b) Convex
(c) Plane           (d) All of the above can produce a virtual  image

12.While using an electric bulb in a street lighting, the reflector should be a
(a) Concave mirror    (b) Convex  mirror
(c) Plane mirror         (d) Cylinderical  mirror

13. When a number of rays starting from a point after suffering reflection or refraction converge to meet or diverge from a second point, then this second point is called
(a) Pole                   (b) Focal point
(c) Object               (d) Image

14. Focal length of a plane mirror is
(a)  0                      (b)  1
(c)  ∞                     (d)  None of these 

15. A man is looking his magnified image in a mirror placed in front of him. The Kind of the mirror he is using is
(a) Plane mirror                       (b) Convex mirror
(c) Concave mirror                  (d) None of these

16. Which of the following is not the case with the image formed by a convex mirror ?
(a)   It is erect                     (b) It is virtual
(c)   It is diminished           (d) It lies beyond the focus

17. A ray of light is reflected at angle 30°. If the angle of incidence becomes double, then the angle of reflection will be

(a) 90°               (b) 60°

(c) 45°               (d) 30°

18.What is the radius of curvature of a plane mirror ?

(a) Zero                                            (b)Between Zero and One

(c) Varies from surface to surface       (d) infinite

19.What type of graph do you expect between 1/u and 1/v for a concave mirror?

(a) parabolic                (b) hyperbolic

(c) straight line            (d) circle

20. A concave mirror has focal length of 0.2 m. The radius of curvature of the mirror is 

(a) +0.2 m                  (b) — 0.2 m

(c) +0.4 m                  (d) — 0.4 m

21. An object is placed in front of a concave mirror of focal length 'f'. The distance of object from mirror when image of same size as of object is obtained is

(a) f                           (b) f/2      

(c) 2f                         (d) 4f

Answers:
 1. c
 2. a
 3. d
 4. a
 5. d
 6. a
 7. c
 8. b
 9. a
10. c
11. d
12. b
13. d
14. c
15. c
16. d
17. b
18. d
19. c
20. d
21. c


Courtesy: R.A.Banwat