CBSE Class 10 Physics Light Reflection and Refraction MCQs Set G

Question: Convex lens focus a real, point sized image at focus, the object is placed
a) At focus
b) Between F and 2F
c) At infinity
d) At 2F
Answer: c

Question: A ray of light is travelling in a direction perpendicular to the boundary of a parallel glass slab. The ray of light:
a) Is refracted towards the normal
b) Is refracted away from the normal
c) Is reflected along the same path
d) Does not get refracted
Answer: d

Question: The SI unit of power of lens is
a) Joule
b) Watt
c) Dioptre
d) J/s
Answer: c

Question: No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be
a) Plane
b) Concave
c) Convex
d) Either plane or convex
Answer: d

Question: What will be the angle of reflection if light falls normally on the reflecting surface?
a) 90°
b) 0°
c) –180°
d) 180°
Answer: b

Question: The focal length of lens depends on:
a) The radii of curvature of its surfaces
b) The refractive index of its material
c) The refractive index of the medium surrounding
d) All of these factors
Answer: d

Question: Light waves spreading from two sources produce interference only if they are:
a) Coherent
b) Transverse
c) Longitudinal
d) None of these
Answer: a

Question: Refractive index of a material for infrared light is:
a) Equal to that for red colour of light
b) Equal to that for ultraviolet light
c) Less than that for ultraviolet light
d) Greater than that for ultraviolet light
Answer: c

Question: Which one of the following materials cannot be used to make a lens?
a) Water
b) Glass
c) Plastic
d) Clay
Answer: d

Question: A deviation in the path of a ray of light can be produced
a) By a glass prism as well as a rectangular glass slab
b) By a rectangular glass slab but not by a glass prism
c) By a glass prism but not by a rectangular glass slab
d) Neither by a glass prism nor by a rectangular glass slab
Answer: a

Question: In order to increase the magnifying power of a microscope:
a) The objective should have larger focal length and eyepiece should have small focal length
b) The focal power of the objective and the eyepiece should be larger
c) The objective should have small focal length and the eyepiece should have larger focal length
d) The focal length of the objective and the eyepiece should be large
Answer: a

Question: The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object?
a) Between the principal focus and the centre of curvature
b) At the centre of curvature
c) Beyond the centre of curvature
d) Between the pole of the mirror and its principal focus
Answer: d

Question: Two lenses of power +3 and -1 diopters are placed in contact. The focal length of the combined lens is:
a) 100 cm
b) 25 cm
c) 50 cm
d) 30.3 cm
Answer: c

Question: Where should an object be placed in front of a convex lens to get a real image of the size of the object?
a) At the principal focus of the lens
b) At twice the focal length
c) At infinity
d) Between the optical centre of the lens and its principal focus
Answer: b

Question: A hunter wants to shoot a fish whose image can be seen through clear water. It is to be aimed:
a) Below the image of fish
b) Above the image of fish
c) Directly towards the image
d) In any direction
Answer: a

Question: Light travel fastest in
a) Water
b) Air
c) Glass
d) Diamond
Answer: b

Question: If in a plano-convex lens the radius of curvature of the convex surface is 10 cm and the focal length of the lens is 30 cm then the refractive index of the material of lens will be:
a) 1.33
b) 3
c) 1.66
d) 1.5
Answer: a

Question: A spherical mirror and a thin spherical lens have each a focal length of –15 cm. The mirror and the lens are likely to be—
a) Both concave
b) Both convex
c) The mirror is concave and the lens is convex
d) The mirror is convex, but the lens is concave
Answer: a

Question: Which of the following lenses would you prefer to use while reading small letters found in a dictionary?
a) A convex lens of focal length 50 cm
b) A concave lens of focal length 50 cm
c) A convex lens of focal length 5 cm
d) A concave lens of focal length 5 cm
Answer: c

Question: The ratio of sine of angle of incidence and the sine of angle of refraction is called as
a) A constant
b) Snell’s law
c) Refractive index of the medium
d) Both b and c
Answer: d

Question: Focal length of convex mirror whose radius of curvature is 32 cm is
a) 32 cm
b) 16 cm
c) 28 cm
d) 8 cm
Answer: b

Question: The mirror having reflecting surface curved inwards
a) Plane mirror
b) Convex mirror
c) Cylindrical mirror
d) Concave mirror
Answer: d

Question: The image formed by a mirror is always straight whatever will be the distance, then mirror is:
a) Only plane
b) Only concave
c) Only convex
d) Either plane or convex
Answer: a

Question: Image formed by a convex spherical mirror is:
a) Virtual
b) Real
c) Enlarged
d) Inverted
Answer: a

Question: An object is approaching a plane mirror at 5 cm/s. A stationary observer sees the image. At what speed will the image appear to approach the stationary observer?
a) 20 cm/s
b) 10 cm/s
c) 15 cm/s
d) 5 cm/s
Answer: d

Question: Read the following sentences carefully, and choose the incorrect one:
a) The process of sending back the light rays which fall on the surface of an object, is called reflection of light.
b) An aluminum metal is one of the worst reflectors of light.
c) The objects having polished surface reflect more light than objects having unpolished, dull surface.
d) The reflection of light in a plane mirror takes place at the silver surface in it.
Answer: b

Question: The deviation of light ray from its path when it travels from one transparent medium to another transparent medium is called
a) Reflection
b) Refraction
c) Dispersion
d) Scattering
Answer: b

Question: Concave mirror is also called as
a) Converging mirror
b) Diverging mirror
c) Both a and b
d) None
Answer: a

Question: The relationship between focal length and radius of curvature is:
a) f = R
b) f = 1/R
c) 2f = R
d) f = 2R
Answer: c

Question: The phenomenon of spreading of light into its constituents is called as
a) Dispersion
b) Refraction
c) Interference
d) Diffraction
Answer: a

Question: A man runs towards the plane mirror at 2 m/s. The relative speed of his image with respect to him will be:
a) 4 m/s
b) 2 m/s
c) 8 m/s
d) 10 m/s
Answer: a

Question: Magnification in case of spherical mirrors is given by
a) M = -u/v
b) M = u/v
c) M = v/u
d) M = -v/u
Answer: d

Question: When the ray is incident at an angle of incidence 90° then
a) There will be reflection
b) There will be no reflection
c) Both a and b
d) Can’t say
Answer: b

Question: A beam of light incident on a plane mirror forms a real image on reflection. The incident beam is:
a) Parallel
b) Convergent
c) Divergent
d) Not certain
Answer: b

Question: A student conducts an activity using a flask of height 15 cm and a concave mirror. He finds that the image formed is 45 cm in height. What is the magnification of the image?
a) -3 times
b) -1/3 times
c) 1/3 times
d) 3 times
Answer: d

Question: If an object is placed symmetrically between two plane mirrors, inclined at an angle of 72°, then total number of images formed:
a) 5
b) 4
c) 2
d) Infinite
Answer: b

Question: The mirror having reflecting surface curved outward
a) Plane mirror
b) Concave mirror
c) Convex mirror
d) Cylindrical mirror
Answer: c

Question: The image of an extended object placed in front of a concave mirror is formed at a distance of 40 cm from the object. If the image is 3 times bigger than the object, the magnitude of focal length of the mirror is
a) 15 cm
b) 10 cm
c) 20 cm
d) 5 cm
Answer: a

Question: The power of a lens is -4.0 D. What is the nature of the lens?
a) Plane
b) Concave
c) Convex
d) Plano convex
Answer: b

Question: The focal length of concave mirror is 15 cm. Its radius of curvature will be:
a) 15 cm
b) 30 cm
c) 45 cm
d) 60 cm
Answer: b

Question: Which of the following statements is true?
a) A convex lens has 4 dioptre power having a focal length 0.25 m
b) A convex lens has -4 dioptre power having a focal length 0.25 m
c) A concave lens has 4 dioptre power having a focal length 0.25 m
d) A concave lens has -4 dioptre power having a focal length 0.25 m
Answer: a

Question: When the object is placed behind C in case of concave mirror then the image formed will be
a) Between F and C
b) Beyond C
c) At infinity
d) At C
Answer: c

Question: The angle of incidence is equal to the
a) Angle of glancing
b) Angle of deviation
c) Angle of reflection
d) Angle refraction
Answer: c

Question: The Angle of Reflection is Equal to the Angle of Incidence:
a) Always
b) Sometimes
c) Under special conditions
d) Never
Answer: a

Question: A doctor has prescribed a corrective lens of power +1.5 D. What type of lens is it?
a) Concave
b) Convex
c) Bifocal
d) None of the above
Answer: b