Chapter 6
1. Through the convex lens, the image is depending upon the focal length.
a. Focal length
b. Object distance
c. Image distance
d. magnification
2. Use to measure the power of a lens is diopter.
a. Diopter
b. Meter
c. Second
d. centimeter
3. A concave lens is diverging.
a. Converging
b. Diverging
c. Neither of these
4. A power of a lens is inversely proportional to its focal length.
a.
Focal length
b.
Object distance
c.
Image distance
d.
magnification
5. A real image is formed on a screen.
a. Real image
b. Virtual image
c. Neither of these
6. If a lens is immersed in water, its focal length is increased.
a. Increased
b. Decreased
c. Constant
d. zero
7. Diffraction and interference of light base on Huygens’ wave theory of light.
a. Huygens’
b. Newton’s
c. Snell’s
8. The focal length of the lens does not depend on the objective distance.
a.
Focal length
b.
Object distance
c.
Image distance
d.
magnification
9. The mirror is one focal points, whereas a lens has two.
a. One
b. Two
c. Three
d. four
10. Concave and convex lens may have considered as a made up of large number of
thin prisms.
a. Thick prism
b. Thin prism
c. Thin glass slab
11. When an object is at 2F of a convex lens the magnification is -1.
a. +2
b. -1
c. -1/2
d. 0
12. A convex lens can be used as a magnifying glass.
a. Convex lens
b. Concave lens
c. Plane mirror
d. Thin glass slab
13. The magnification of concave lens is between 0 and +1.
a. 0 and +1
b. 0 and -1
c. +1 and 10
d. -1 and +1
14. The focus of a convex lens is real.
a. Real
b. Virtual
c. Neither of these
15. The power of a lens of focal length -0.2 m is -5D.
a. – 5 D
b. +5D
c. -2D
d. +10 D
16. If an object is placed at F of a concave lens the image is between P and F.
a. At infinity
b. Beyond 2F
c. Between P and F
d. At 2F
17. The virtual image formed by a convex lens is larger than the object.
a. Larger than the object
b. Smaller than the object
c. Same size as the object
18. A converging lens of focal length F can be used as magnifying glass is the
distance of the object from the lens less than F.
a. Less than F
b. Equal to F
c. Between F and 2F
19. Convex lens is used in camera.
a. Camera
b. Periscope
c. Light pipe
20. The lens has at least two curve surfaces.
a. one
b. two
c. three
d. four
21. A biconvex lens features _____.
a.
b.
c.
d.
two concave sides
two convex sides
one concave and one convex side
neither concave nor convex side
22. When parallel light rays pass through a convex lens, the refracted rays converge at a point known as
the _____.
a.
b.
c.
d.
focal length
focal point
focus
principal focus
23. A prime lens has _____.
a.
b.
c.
d.
varying focal lengths
fixed focal length
both fixed and varying focal lengths
neither fixed nor varying focal lengths
24. State true or false: Convex lens diverges the beam of light.
a. TRUE
b. FALSE
25. Which lens is thinner at the center?
a.
Concave lens
b. Convex lens
c. A mirror
d. Planar lens
26. The lens in the human eye is _____?
a.
b.
c.
d.
Concave lens
Convex lens
A mirror
Planar lens
27. A convex lens is an optical lens with a convex and flat surface is-----a. Plano- convex
b. biconvex
c. converging meniscus
28. Which type of lens is used in a magnifying glass?
a.
b.
c.
d.
Concave lens
Convex lens
A mirror
Planar lens