Choose the correct alternatives and rewrite the complete sentences
MIRROR
1. The image formed by a concave mirror is ..................... .
(a) always virtual and erect
(b) always virtual and inverted
(c) virtual if the object is placed between the pole and the focus
(d) virtual if the object is beyond the focus
2. A concave mirror forms a virtual image of an object placed ..................... .
(a) at infinity
(b) at the centre of curvature of the mirror
(c) at the focus of the mirror
(d) between the focus and the mirror
3. A convex mirror always forms an image which is ..................... than the object size.
(a) larger (b) smaller (c) double (d) three times
4. No matter how far you stand from a spherical mirror, your image appears erect. The mirror may be ..................... .
(a) Plane (b) concave (c) convex (d) either plane or convex
5. In case of a concave mirror, an erect image is ..................... .
(a) real and enlarged (b) real and diminished
(c) virtual and diminished (d) virtual and enlarged
6. ..................... images can be displayed on a screen.
(a) Virtual (b) Real (c) Virtual and erect (d) Virtual and inverted
7. A rear view mirror of a car is ..................... .
(a) Plane mirror (b) Concave mirror
(c) Convex mirror (d) Cylindrical mirror
8. An image of an object placed at infinite distance from a concave mirror is formed at ..................... .
(a) the focus of the mirror (b) behind the mirror (c) centre of curvature (d) infinity
9. The distance of focus F from the pole P is termed as the ..................... of the mirror.
(a) radius of curvature (b) centre of curvature (c) principal axis (d) focal length
10. A concave mirror is also called as a ..................... mirror.
(a) converging (b) diverging (c) plane (d) outward curved
*11. A ray of light parallel to principal axis after reflection from concave mirror passes through ..................... .
(a) centre of curvature (b) focus (c) pole (d) optical centre
12. The centre of the spherical mirror is called ..................... .
(a) pole (b) centre of curvature (c) principal axis (d) focus
13. The image made by a plane mirror is a ..................... image.
(a) real (b) virtual (c) inverted (d) diminished
14. According to the new sign convention, the ..................... of the mirror is taken as origin.
(a) focus (b) pole (c) optical centre (d) centre of curvature
15. Turning back of light from the surface on which it falls is called ..................... .
(a) refraction (b) reflection of light (c) dispersion (d) rectilinear propagation
16. The size of the image of an object placed at the focus of a concave mirror is
..................... .
(a) erect (b) highly enlarged (c) same size (d) diminished
17. A convex mirror is also called as a ..................... mirror.
(a) converging (b) plane (c) diverging (d) inward curved
18. To obtain a real, inverted and enlarged image using a concave mirror, the
object should be placed ..................... .
(a) between the focus and centre of curvature of the mirror
(b) at infinity
(c) beyond centre of curvature
(d) at centre of curvature
19. If magnification is negative, the image is ..................... with respect to the
object.
(a) inverted (b) enlarged (c) erect (d) diminished
LENS
20. The image formed by a concave lens ..................... .
(a) is always virtual and erect
(b) is always real and inverted
(c) is virtual if the object is placed between the optical centre and the focus
(d) Is virtual if the object is beyond the focus
*21. The focal length of ..................... lens is positive.
(a) concave (b) bifocal (c) convex (d) double concave
*22. The image of an object is formed behind ..................... in hypermetropia.
(a) cornea (b) retina (c) lens (d) iris
*23. An optical device used by watch repairers is ..................... .
(a) compound microscope (b) telescope (c) simple microscope (d) spectrometer
*24. The power of spectacle for myopic eye is ..................... .
(a) positive (b) negative (c) zero (d) positive and negative
25. The human eye can focus objects at different distances adjusting the focal length of the eye due to ..................... .
(a) presbyopia (b) power of accomodation (c) hypermetropia (d) myopia
26. The tendency of pupil to adjust the opening for light is called ..................... .
(a) adaptation (b) power of accomodation (c) light control (d) perception
27. A lens does not produce any deviation of a ray of light passing through its ..................... .
(a) centre of curvature (b) optical centre (c) second focal point (d) axial point at a distance of 2F
28. The power of a convex lens of focal length 25 cm is ..................... .
(a) 4 dioptre (b) -4 dioptre (c) 1/25 dioptre (d) -1/25 dioptre
29. A person suffering from myopia ..................... .
(a) cannot see nearby objects clearly
(b) cannot see distant object clearly
(c) can see nearby as well as distant objects clearly
(d) can neither see nearby objects nor distant objects clearly
30. A well lit object produces ..................... incident rays.
(a) two (b) three (c) finite (d) infinite
31. The change in focal length of the eye to view objects at different distances is brought about by the ..................... .
(a) retina (b) ciliary muscles (c) pupil (d) iris
32. The least distance of distinct vision is about ..................... .
(a) 30 cm (b) 35 cm (c) 20 cm (d) 25 cm
A. Answers.
1. Virtual if the object is placed between the pole and the focus
2. Between the focus and the mirror
3. Smaller
4. Convex
5. Virtual and enlarged
6. Real
7. Convex mirror
8. The focus of the mirror
9. Focal length
10. Converging
11. Focus
12. Pole
13. Virtual
14. Pole
15. Reflection of light
16. Highly enlarged
17. Diverging
18. Between the focus and center of curvature of the mirror
19. Inverted
20. Is always virtual and erect
21. Convex
22. Retina
23. Simple microscope
24. Negative
25. Power of acomodation
26. Adaptation
27. Optical centre
28. 4 dioptre
29. Cannot see the distant object clearly
30. Infinite
31. Ciliary muscle
32. 25 cm