CBSE Class 10 Physics Light Reflection and Refraction MCQs Set I

Question: A student obtains a blurred image of a distant object on a screen using a convex lens. To obtain a distinct image on the screen he should move the lens
a) away from the screen
b) towards the screen
c) to a position very far away from the screen
d) either towards or away from the screen depending upon the position of the object
Answer: d

Question: In torches, search lights and headlights of vehicles, the bulb is placed
a) between the pole and the focus of the reflector
b) very near to the focus of the reflector
c) between the focus and centre of curvature of the reflector
d) at the centre of curvature of the reflector
Answer: b

Question: To determine the approximate value of the focal length of a given concave mirror, the image of a distant object formed by the mirror on a screen is always
a) Laterally inverted and diminished
b) Inverted and diminished
c) Erect and diminished
d) Erect and highly diminished
Answer: b

Question: The laws of reflection hold true for
a) plane mirrors only
b) concave mirrors only
c) convex mirrors only
d) all reflecting surfaces
Answer: d

Question: A student determines the focal length of a device ‘X’ by focussing the image of a distant object on a screen placed 20 cm from the device on the same side as the object. The device ‘X’ is
a) Concave lens of focal length 10 cm
b) Convex lens of focal length 20 cm
c) Concave mirror of focal length 10 cm
d) Concave mirror of focal length 20 cm
Answer: d

Question: Which of the following can make a parallel beam of light when light from a point source is incident on it?
a) Concave mirror as well as convex lens
b) Convex mirror as well as concave lens
c) Two plane mirrors at 90°
d) Concave mirror as well as concave lens
Answer: a

Question: In your laboratory, tracing the path of light through a glass slab shows
a) ∠i is more than ∠r, but nearly equal to ∠e
b) ∠i is less than ∠r, but nearly equal to ∠e
c) ∠i is more than ∠e, but nearly equal to ∠r
d) ∠i is less than ∠e, but nearly equal to ∠r
Answer: a

Question: A spherical mirror and a thin spherical lens both have focal length -15 cm. They are likely to be
a) both concave
b) both convex
c) concave mirror and convex lens
d) convex mirror and concave lens
Answer: a

Question: Rays from the sun converge at a point 15 cm in front of a concave mirror. For an image of equal size to be formed, the object must be placed
a) 15 cm in front
b) 30 cm in front
c) between 15 cm and 30 cm
d) more than 30 cm in front
Answer: b

Question: Magnification produced by a rear-view mirror in vehicles
a) is less than one
b) is more than one
c) is equal to one
d) can be more or less than one
Answer: a

Question: Which lens would you prefer while reading very small letters?
a) Convex lens of focal length 50 cm
b) Concave lens of focal length 50 cm
c) Convex lens of focal length 5 cm
d) Concave lens of focal length 5 cm
Answer: c

Question: When an object is kept within the focus of a concave mirror, the enlarged image formed behind the mirror is
a) real
b) inverted
c) virtual and inverted
d) virtual and erect
Answer: d

Question: A student focuses a distant building to get a more correct focal length of a concave mirror. To get the image on the same screen he should move the
a) mirror away from the screen
b) screen away from the mirror
c) screen towards the mirror
d) screen towards the building
Answer: c

Question: If the image of a distant object formed by a convex lens on a screen is blurred, the lens should be moved
a) away from the screen
b) towards the screen
c) very far from the screen
d) either towards or away depending on object distance
Answer: d

Question: An optical device forms an image of the sun on a screen 24 cm away on the same side. The device is
a) Convex mirror of focal length 12 cm
b) Convex lens of focal length 24 cm
c) Concave mirror of focal length 24 cm
d) Convex lens of focal length 12 cm
Answer: c

Question: A teacher placed a convex lens of focal length 15 cm at 42.7 cm mark. The correct screen position for a distant tree image is
a) 12.7 cm
b) 29.7 cm
c) 57.7 cm
d) 72.7 cm
Answer: c

Question: While tracing ray through a glass slab a student finds
a) ∠i > ∠r > ∠e
b) ∠i = ∠e > ∠r
c) ∠i < ∠r < ∠e
d) ∠i = ∠e < ∠r
Answer: b

Question: The image of a distant object formed on a screen with a convex lens is always
a) erect and laterally inverted
b) erect and diminished
c) inverted and diminished
d) virtual, inverted and diminished
Answer: c

Question: Suppose a convex lens focuses a candle image on screen. To focus parallel sunrays on the same screen, move lens
a) slightly towards the screen
b) slightly away from the screen
c) slightly towards the sun
d) lens and screen both towards sun
Answer: a

Question: Properties of virtual images
a) (i) and (iv)
b) (i) and (ii)
c) (i), (ii) and (iii)
d) (i), (ii) and (iv)
Answer: c

Question: A real image is formed by light rays after reflection or refraction when they
a) (i) and (iv)
b) (ii) and (iv)
c) (i) and (ii)
d) (ii) and (iii)
Answer: c

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

Assertion And Reason Based MCQs :

Directions : In the following questions, A statement of Assertion (a) is followed by a statement of Reason (R). Mark the correct choice as.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is NOT the correct explanation of A.
(c) A is true but R is false.
(d) A is false and R is True.

Question: Assertion (A): The image formed by a concave mirror is certainly real if the object is virtual.
Reason (R): The image formed by a concave mirror is certainly virtual if the object is real.
Answer: c

Question: Assertion: Light travels faster in glass than in air.
Reason: Glass is denser than air.
Answer: d

Question: Assertion (A): If the rays are diverging after emerging from a lens; the lens must be concave.
Reason (R): The convex lens can give diverging rays.
Answer: d

Question: Assertion (A): The refractive index of diamond is √6 and refractive index of a liquid is √3 . If the light travels from diamond to the liquid, it will be initially reflected when the angle of incidence is 30°.
Reason (R): µ = 1/sin C, where m is the refractive index of diamond with respect to liquid.
Answer: a

Question: Assertion (A): Plane mirror may form real image.
Reason (R): Plane mirror forms virtual image, if object is real.
Answer: b

Question Assertion (A): The focal length of the convex mirror will increase, if the mirror is placed in water.
Reason (R): The focal length of a convex mirror of radius R is equal to, f =R/2.
Answer: d

Question: Assertion (A): Refractive index of glass with respect to air is different for red light and violet light.
Reason (R): Refractive index of a pair of media depends on the wavelength of light used.
Answer: a

Question: Assertion (A): An object is placed at a distance of f from a convex mirror of focal length f, its image will form at infinity.
Reason (R): The distance of image in convex mirror can never be infinity.
Answer: d

Case Based Questions : 

Read the following passage and answer any four questions from A student wants to project the image of a candle flame on the walls of the school laboratory by using a mirror.

Question: Which type of mirror should he use and why?
a) Convex mirror, it forms virtual image
b) Concave mirror, it forms virtual image
c) Concave mirror, it forms real image
d) Convex mirror, it forms real image
Answer: c

Question: If the image formed by this mirror is inverted and real, the magnification will be:
a) Positive
b) Negative
c) Either of them
d) None of the above
Answer: b

Question: A virtual image formed by concave mirror is:
a) erect and enlarged
b) erect and diminished
c) inverted and diminished
d) inverted and enlarged
Answer: a

Question: At what distance, in terms of focal length ‘f’ of the mirror, should he place the candle flame to get the magnified image on the wall?
a) At F
b) Between F and C
c) At C
d) At infinity
Answer: b

Question: To get the diminished image of the candle flame, the object must be placed at:
a) infinity
b) at C
c) between F and C
d) At F
Answer: a 

Read the following passage and answer any four questions from A student wants to project the image of a candle flame on a screen 60 cm in front of a mirror by keeping the flame at a distance of 15 cm from its pole.

Question: When object distance is less than focal length the image is _______ and when object distance is more than focal length the image is ______.
a) real in both case
b) virtual in both case
c) real, virtual
d) virtual, real
Answer: d

Question: What is the distance between the object and its image?
a) 45 cm
b) 35 cm
c) 75 cm
d) 0 cm
Answer: a

Question: Suggest the type of mirror he should use:
a) convex mirror
b) plane mirror
c) concave mirror
d) none of the above
Answer: c

Question: Find the linear magnification of the image produced.
a) –4
b) +4
c) –900
d) +900
Answer: a

Question: The image formed in the above case is:
a) virtual, inverted and magnified
b) real, erect and magnified
c) real, inverted and magnified
d) real, erect and diminished
Answer: c 

Read the following passage and answer the following questions from A student focuses the image of a candle flame, placed at about 2 m from a convex lens of focal length 10 cm, on a screen. After that he moves gradually the flame towards the lens and each time focuses its image on the screen.

Question: What difference is seen in the intensity (brightness) of the image of the flame on the screen?
a) intensity of image increases
b) intensity of image remains same
c) intensity of image reduces
d) the image disappears
Answer: a

Question: What is seen on the screen when the flame is very close (about 5 cm) to the lens?
a) a bright image
b) a magnified image
c) diminished image
d) no image
Answer: d

Question: In which direction does he move the lens to focus the flame on the screen?
a) away from screen
b) towards the screen
c) should not move the screen
d) toward the candle
Answer: d

Question: What happens to the size of the image of the flame formed on the screen?
a) size of image will decrease
b) size of image will increase
c) remains unchanged
d) size will become too small
Answer: b