Practice
Exercise
1. Which one
of the following is thenatural source of light?
(a) Sun
(b)
Tubelight
(c) Electric
bulb
(d) None of
the above
2. What type
of mirror can be used to obtain the real image of an object?
(a) Plane
mirror
(b) Concave
mirror
(c) Convex
mirror
(d) No
mirror can produce a real image
3. An erect
and enlarged image can be formed by
(a) only a
convex mirror
(b) only a
concave mirror
(c) only a
plane mirror
(d) Both
convex and concave mirrors
4. Which of
the following can be o used to form a real image?
(a) Only
concave mirror
(b) Only plane mirror
(c) Only
convex mirror
(d) Both
concave and convex mirrors
5. The
mirror used by a dentist is a
(a)
cylindrical mirror
(b) concave
mirror
(c) convex
mirror
(d) plane
mirror
6. The
minimum length of a plane mirror in which is person can see himself full length
should be
(a) equal of
his height
(b) slightly
more than his height
(c) half his
height
(d) one
fourth his height
7. A person
standing in front of a mirror finds his image thinner but with normal height.
The mirror in question is
(a) concave
and spherical
(b) convex
and spherical
(c) convex
and cylindrical with axis vertical
(d) convex
and cylindrical with axis horzontal
8. At
sunrise or sunset, the sun appears red. This is because..
(a) The sun
is colder at sunrise or sunset
(b)
Scattering due to dust particles and air molecule causes this phenomenon
(c)
Refraction causes this phenomenon
(d)
Diffraction sends red rays to the earth at these times
9. The clear
sky looks blue because of
(a)
reflection of light
(b)
refraction of light
(c)
diffraction of light
(d)
dispersion of light
10. Swimming
pools appear shallower than they actually are because of
(a)
reflection
(b)
refraction
(c) Both (a)
and (b)
(d) None of
the above
11. An air
bubble inside water behaves
(a) concave
lens
(b)
concave-convex lens
(c)
plano-convex lens
(d) convex
lens
12. The
image of an object formed by a device is always virtual and small The device in
question is a
(a) concave
lens
(b) concave
mirror
(c) convex
(d) glass
plate
13. 1f half
of the body of a lens is covered with black paper the image produced by the
lens will
(a)have its
size reduced to half
(b)
disappear
(c) have its
intensity reduced to hall
(d) Nome of
the above
14. Which
one of the following optical Instruments produce a virtual image?
(a) A simple
magnifier
(b)Movie
projector
(c)An
ordinary single lens reflex camera
(d) None of
the above
15. The
focal length of a convex lens various colours of light is
(a) same for
all colours
(b) shorter
for blue than for red
(c) shorter
for red than for blue
(d) maximum
for yellow
16. Which
colour of light is dispersed most by a prism?
(a) Yellow (b) Red
(c) Blue (d) Green
17. A person
having Hypermetropia can't see nearby objects clearly because the image of nearby
objects is formed.
(a) In front
of the pupil
(b) In front
of the retina
(c) Behind
the retina
(d) On the
retina
18. A man
cannot see an object distinctly at a distance less the Im. He is suffering from
for
(a)
astigmatism
(b)
distortion
(c) myopia
(d)
hypermetropia
19. Focal
length of the eye-lens which enables us to see the object at varying distances,
is controlled and changed by
(a) retina
(b) ciliary
muscles
(c) choroid
(d) vitreous
humour
20. The
principle of working of periscope is based on
(a)
reflection only
(b)
refraction only
(c)
refection and refraction
(d)
reflection and interference
Answers- 1.
(a) 2. (a) 3. (b) 4. (a) 5. (b) 6. (a) 7. (a) 8. (c) 9. (b) 10. (b)
11. (a) 12. (a) 13. (c) 14. (a) 15. (b)
16. (b) 17. (c) 18. (d) 19. (b) 20. (c)
