Extra 40 MCQs with answers from the Chapter:9 Light - Reflection and Refraction (Class 10 CBSE Science):
Which type of mirror always forms a virtual and erect image?
a) Concave mirror
b) Convex mirror
c) Plane mirror
d) Both b and c
Answer:
d) Both b and c
The focal length of a plane mirror is:
a) Infinite
b) Zero
c) Negative
d) None of these
Answer:
a) Infinite
A concave mirror forms a virtual and magnified image when the object is placed:
a) At infinity
b) Between the focus and the pole
c) Beyond the
centre
of curvature
d) At the
centre
of curvature
Answer:
b) Between the focus and the pole
What is the nature of the image formed by a convex mirror for any position of the object?
a) Real and inverted
b) Virtual and erect
c) Real and erect
d) Virtual and inverted
Answer:
b) Virtual and erect
A concave mirror is used in which of the following applications?
a)
Rear-view
mirrors in vehicles
b) Street lights
c) Solar cookers
d) Both a and b
Answer:
c) Solar cookers
If the magnification produced by a mirror is -2, what does the negative sign indicate?
a) Image is erect
b) Image is real and inverted
c) Image is virtual and erect
d) Image is on the same side as the object
Answer:
b) Image is real and inverted
Which of the following is the mirror formula?
a) 1f=1v−1u\frac{1}{f} = \frac{1}{v} - \frac{1}{u}f1=v1−u1
b) 1f=1u+1v\frac{1}{f} = \frac{1}{u} + \frac{1}{v}f1=u1+v1
c) f=
u+vf
= u +
vf
=
u+v
d) f=
uvu+vf
= \frac{
uv
}{
u+v
}f=
u+vuv
Answer:
b) 1f=1u+1v\frac{1}{f} = \frac{1}{u} + \frac{1}{v}f1=u1+v1
An object is placed at the focus of a concave mirror. The image formed is:
a) At the focus
b) At infinity
c) Between focus and
centre
of curvature
d) Behind the mirror
Answer:
b) At infinity
Which type of mirror is used in a vehicle's
rear-view
mirror?
a) Concave
b) Convex
c) Plane
d) Parabolic
Answer:
b) Convex
The focal length of a convex mirror is always:
a) Positive
b) Negative
c) Zero
d) Infinity
Answer:
a) Positive
Which of the following represents Snell’s law?
a) n1sini=n2sinrn_1 \sin
i
= n_2 \sin rn1
sini
=n2
sinr
b) 1f=1u+1v\frac{1}{f} = \frac{1}{u} + \frac{1}{v}f1=u1+v1
c) v=
u+atv
= u +
atv
=
u+at
d) P=1fP = \frac{1}{f}P=f1
Answer:
a) n1sini=n2sinrn_1 \sin
i
= n_2 \sin rn1
sini
=n2
sinr
What happens to light when it travels from a rarer medium to a denser medium?
a) It bends away from the normal
b) It bends towards the normal
c) It does not change direction
d) It disappears
Answer:
b) It bends towards the normal
The unit of the refractive index is:
a) m
b) cm
c) No unit
d)
Dioptre
Answer:
c) No unit
Which of the following has the highest refractive index?
a) Water
b) Air
c) Diamond
d) Glass
Answer:
c) Diamond
The speed of light is maximum in:
a) Water
b) Glass
c) Air
d) Vacuum
Answer:
d) Vacuum
A real and inverted image of the same size as the object is formed by a convex lens when the object is placed at:
a) Infinity
b) Focus
c) Twice the focal length
d) Between focus and
centre
of curvature
Answer:
c) Twice the focal length
Which lens is used to correct myopia (short-sightedness)?
a) Convex lens
b) Concave lens
c) Cylindrical lens
d) None of these
Answer:
b) Concave lens
A convex lens always forms a virtual and magnified image when the object is placed:
a) At infinity
b) At the focus
c) Between the focus and optical
centre
d) Beyond twice the focal length
Answer:
c) Between the focus and optical
centre
The power of a lens is given by:
a) P=1fP = \frac{1}{f}P=f1
b) P=
fP
=
fP
=f
c) P=
uvP
=
uvP
=
uv
d) P=
uvP
= \frac{u}{v}P=vu
Answer:
a) P=1fP = \frac{1}{f}P=f1
The SI unit of power of a lens is:
a) Meter
b) Hertz
c)
Dioptre
d) Newton
Answer:
c)
Dioptre
A convex lens has a focal length of 20 cm. Its power is:
a) +5 D
b) -5 D
c) +10 D
d) -10 D
Answer:
a) +5 D
A concave mirror always forms a real image when the object is placed:
a) Between focus and pole
b) At the
centre
of curvature
c) At infinity
d) Both b and c
Answer:
d) Both b and c
Which lens is used in a magnifying glass?
a) Concave lens
b) Convex lens
c) Cylindrical lens
d) None of these
Answer:
b) Convex lens
If the focal length of a lens is -15 cm, it is a:
a) Convex lens
b) Concave lens
c) Concave mirror
d) Plane mirror
Answer:
b) Concave lens
Which lens is used in a simple microscope?
a) Convex lens
b) Concave lens
c) Plane mirror
d) None of these
Answer:
a) Convex lens
What is the relation between focal length (f) and the radius of curvature (R) of a spherical mirror?
a) f=R4f = \frac{R}{4}f=4R
b) f=Rf = Rf=R
c) f=R2f = \frac{R}{2}f=2R
d) f=2Rf = 2Rf=2R
Answer:
c) f=R2f = \frac{R}{2}f=2R
Which type of mirror is used in searchlights and torches?
a) Convex mirror
b) Concave mirror
c) Plane mirror
d) Parabolic mirror
Answer:
b) Concave mirror
The image formed by a plane mirror is always:
a) Real and inverted
b) Virtual and inverted
c) Virtual and erect
d) Real and erect
Answer:
c) Virtual and erect
A convex mirror is used as a rear-view mirror because:
a) It gives an erect and diminished image
b) It gives a real and magnified image
c) It gives a real and inverted image
d) It forms a virtual and enlarged image
Answer:
a) It gives an erect and diminished image
A concave mirror forms a real image when the object is placed:
a) Between the pole and the focus
b) Beyond the focus
c) Between focus and
centre
of curvature
d) Only at infinity
Answer:
b) Beyond the focus
Which of the following laws is not true for refraction of light?
a) The incident ray, refracted ray, and normal all lie in the same plane
b) The angle of incidence is always equal to the angle of refraction
c) The ratio
sinisinr
\frac{\sin
i
}{\sin r}
sinrsini
is a constant for a given medium
d) Light bends towards the normal when it enters a denser medium
Answer:
b) The angle of incidence is always equal to the angle of refraction
When light enters from air to glass, its speed:
a) Increases
b) Decreases
c) Remains the same
d) First increases then decreases
Answer:
b) Decreases
A ray of light is incident at 30° to the normal on a plane mirror. What is the angle of reflection?
a) 30°
b) 60°
c) 90°
d) 0°
Answer:
a) 30°
When a light ray travels from a denser medium to a rarer medium, it bends:
a) Towards the normal
b) Away from the normal
c) Does not bend
d) Along the normal
Answer:
b) Away from the normal
Which of the following has the lowest refractive index?
a) Water
b) Glass
c) Air
d) Diamond
Answer:
c) Air
A convex lens of focal length 20 cm is used to form an image. What is its power?
a) +5 D
b) -5 D
c) +10 D
d) -10 D
Answer:
a) +5 D
A concave lens always forms:
a) Real and inverted image
b) Virtual and erect image
c) Enlarged and real image
d) No image
Answer:
b) Virtual and erect image
A magnification of +2 by a mirror indicates:
a) The image is real and inverted
b) The image is virtual and erect
c) The image is diminished
d) The mirror is concave and forms an image at infinity
Answer:
b) The image is virtual and erect
What will be the nature of the image formed by a convex lens when the object is placed at twice the focal length?
a) Virtual and erect
b) Real and inverted
c) Diminished and real
d) Highly magnified and real
Answer:
b) Real and inverted
If the power of a lens is -2D, then the lens is:
a) Convex
b) Concave
c) Plane
d) None of these
Answer:
b) Concave
