Light Reflection and Refraction Class 10 MCQ

Class 10 Science Chapter 9 MCQ Light Reflection and Refraction

MCQ on Light Reflection and Refraction Class 10

Select and write the most appropriate option of the four options for each of the questions :

Question 1.
In which of the following is a concave mirror used? ( )
A) A solar cooker
B) A rear view mirror in vehicles
C) A safety mirror in shopping malls
D) In viewing full size image of distant tall buildings.
Answer:
A) A solar cooker

Question 2.
The following diagram shows the use of an optical device to perform an experiment of light. As per the arrangement shown, the optical device is likely to be a ( )

A) Concave mirror
B) Concave lens
C) Convex mirror
D) Convex Lens
Answer:
B) Concave lens

Question 3.
For the diagram shown, according to the new cartesian sign convention the magnification of the image formed will have the following specifications: ( )

A) Sign – Positive, Value – Less than 1
B) Sign – Posit Ive, Value – More than 1
C) Sign – Negative, Value – Less than 1
D) Sign – Negative, Value – More than 1
Answer:
B) Sign – Posit Ive, Value – More than 1

Question 4.
A ray of light is incident as shown. if A, B and C are three different transparent media, then which among the following options is true for the given diagram? ( )

A) <1>∠4
B) ∠1<∠2
C) ∠3 =∠2
D)∠3 > ∠4
Answer:
C) ∠3 =∠2

Question 5.
If a lens can converge the sun rays at a point 20 cm, away from its optical centre, the power of this lens is ( )
A) + 2D
B) – 2D
C) + 5D
D) – 5D
Answer:
C) + 5D

Question 6.
The radius of curvature of a converging mirror is 30 cm. At what distance from the mirror should an object be placed so as to obtain a virtual image? ( )
A) Infinity
B) 30 cm
C) Between 15 cm and 30 cm
D) Between 0 cm and 15 cm
Answer:
D) Between 0 cm and 15 cm

Question 7.
A converging lens forms a three times magnified inside of an object, which can be taken on a screen. If the focal length of the lens is 30 cm, then the distance of the object from the lens is
A) – 55cm
B) – 50 cm
C) – 45cm
D) – 40cm
Answer:
D) – 40cm

Question 8.
Which of the following statements is not true in reference to the diagram shown below? ( )

A) Image formed is real.
B) Image formed is enlarged.
C) Image is formed at a distance equal to double the focal length.
D) Image formed is inverted
Answer:
B) Image formed is enlarged.

Question 9.
The refractive index of medium A is 1.5 and that of medium B is 1.33. It the speed of
light in air is 3 x 10⁸ m/s, what is the speed of light in medium A and B respectively.
A) 2 x 10⁸ m/s and 1.33 x 10 m/s
B) 1.33 x 10⁸ m/s and 2 x 10⁸ m/s
C) 2.25 x 10⁸ m/s and 2 x 10⁸ m/s
D) 2 x 10⁸ m/s and 2.25 x 10⁸ m/s
Answer:
D) 2 x 10⁸ m/s and 2.25 x 10⁸ m/s

Question 10.
An object of height 4 cm is kept at a distance of 30 cm from the pole of a diverging mirror. If the focal length of the mirror is 10 cm, the height of the image formed is
A) +3.0 cm
B) +2.5 cm
C) +1.0 cm
D) +0.75cm
Answer:
C) +1.0 cm

Question 11.
When an object is kept within the focus of a concave mirror, an enlarged image is formed behind the mirror. This image is :
A) real
B) inverted
C) virtual and inverted
D) virtual and erect
Answer:
D) virtual and erect

Question 12.
For a real object, which of the following can produce a real image ?
A) plane mirror
B) concave mirror
C) concave lens
D) convex mirror
Answer:
B) concave mirror

Question 13.
Which of the following mirror is used by a dentist to examine a small cavity? ( )
A) convex mirror
B) plane mirror
C) concave mirror
D) combination of convex and concave mirror
Answer:
C) concave mirror

Question 14.
An object at a distance of 30 cm from a concave mirror gets its image at the same point. The focal length of the mirror is
A) -30 cm
B) 30 cm
C) -15 cm
D) +15 cm
Answer:
C) -15 cm

Question 15.
An object at a distance of +15 cm is slowly moved towards the pole of a convex mirror. The image will get
A) shortend and real
B) enlarged and real
C) enlarged and virtual
D) diminished and virtual
Answer:
D) diminished and virtual

Question 16.
A concave mirror of radius 30 cm is placed in water. Its focal length in air and water differs by
A) 15
B) 20
C) 30
D) 0
Answer:
D) 0

Question 17.
A concave mirror of focal length 20 cm forms an image having twice the size of object. For the virtual position of image, the position of object will be at
A) 25 cm
B) 40 cm
C) 10 cm
D) At infinity
Answer:
C) 10 cm

Question 18.
The nature of the image formed by concave mirror when the object is placed between the focus (F) and centre of curvature (C) of the mirror observed by us is ( )
A) real, inverted and diminished
B) virtual, erect and smaller in size
C) real, inverted and enlarged
D) virtual, upright and enlarged
Answer:
C) real, inverted and enlarged

Question 19.
If a man’s face is 25 cm in front of concave shaving mirror producing an erect image 1.5 times the size of face, focal length of the mirror would be
A) 75 cm
B) 25 cm
C) 15 cm
D) 60 cm
Answer:
A) 75 cm

Question 20.
The angle of incidence ‘i’ and refraction ‘r’ are equal in a transparent slab when the value of i is…………..
A) 0°
B) 45°
C) 90°
D) depend on the material of the slab
Answer:
A) 0°

Question 21.
The refractive index of water is 1.33. The speed of light in water will be
A) 1.33 × 10⁸ m/s
B) 3 × 10⁸ m/s
C) 2.26 × 10⁸ m/s
D) 2.66 × 10⁸ m/s
Answer:
C) 2.26 × 10⁸ m/s

Question 22.
You are given three media A, B and C of refractive index 1.33,1.65 and 1.46. The medium in which the light will travel fastest is
A) A
B) B
C) C
D) equal in all three media
Answer:
A) A

Question 23.
A divergent lens will produce
A) always real image
B) always virtual image
C) both real and virtual image
D) none of these
Answer:
B) always virtual image

Question 24.
When object moves closer to convex lens, the image formed by it shift
A) away from the lens
B) towards the lens
C) first towards and then away from the lens
D) none of these
Answer:
A) away from the lens

Question 25.
When object moves closer to a concave lens the image formed by it shifts
A) away from the lens on the same side of object
B) toward the lens
C) away from the lens on the other side of lens
D) first towards and then away from the lens
Answer:
B) toward the lens

Question 26.
A real image is formed by the light rays after reflection or refraction when they
a) actually meet intersect with each other
b) actually converge at a point
c) appear to meet when they are produced in the backward direction
d) appear to diverge from a point
Which of the above statements are correct?
A) a and d
B) b and d
C) a and b
D) b and c
Answer:
C) a and b

Question 27.
A 10 mm long awl pin is placed vertically in front of concave mirror. A 5 mm long image of the awl pin is formed at 30 cm is front of the mirror. The focal length of this mirror is
A) -30 cm
B) -20 cm
C) -40 cm
D) -60 cm
Answer:
B) -20 cm

Question 28.
A light ray enters from medium A to medium B as shown in figure. The refractive index of medium B relative to A will be

A) greater than unity
B) less than unity
C) equal to unity
D) zero
Answer:
B) less than unity

Question 29.
Which of the following statements is / are 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 having a focal 0.25 m
Answer:
A) A convex lens has 4 dioptre power having a focal length 0.25 m

Question 30.
Magnification produced by a rear view mirror fitted in vehicles
A) is less than one
B) is more than one
C) is equal to one
D) can be more than or less than one depending upon the position of the object in front of it
Answer:
A) is less than one

Question 31.
A full length image of a distant tall building can definitely be seen by using ( )
A) a concave mirror
B) a convex mirror
C) a plane mirror
D) both concave as well as plane mirror
Answer:
B) a convex mirror

Question 32.
In torches, search light 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) very near to the focus of the reflector

Question 33.
The laws of reflection hold good for
A) plane mirror only
B) concave mirror only
C) convex mirror only
D) all mirrors irrespective of their shape
Answer:
D) all mirrors irrespective of their shape

Question 34.
The path of a ray of light coming from air passing through a rectangular glass slab traced by four students is shown as a, b, c and d in the given Figure. Which one of them is correct?

A) a
B) b
C) c
D) d
Answer:
B) b

Question 35.
In which of the following, the image of an object placed at infinity will be highly diminished and point sized ?
A) concave mirror only
B) convex mirror only
C) convex lens only
D) concave mirror, convex mirror, concave lens and convex lens
Two statements are given below as Assertion (A) and Reason (R). Read the statements and choose the correct option
Answer:
D) concave mirror, convex mirror, concave lens and convex lens

Question 36.
Assertion (A): A convex mirror is used as driver’s mirror.
Reason (R): Images formed in a convex mirror are diminished.
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 but R is true.
Answer:
B) Both A and R are true but R is not the correct explanation of A.

Question 37.
Assertion (A): In going from a denser to a rarer medium, a ray of light bends away from normal.
Reason (R): This occurs because light travels faster in a rarer medium than in a denser medium.
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 but R is true.
Answer:
A) Both A and R are true and R is the correct explanation of A.

Question 38.
Assertion (A): When a convex lens of power +2D is held in contact with a concave lens of power -4 D, the combination has a focal length of -0.5 cm
Reason (R) : P = P₁+P₂
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 but R is true.
Answer:
B) Both A and R are true but R is not the correct explanation of A.

Question 39.
Assertion (A): Large concave mirrors are used to concentrate sunlight to produce heat in solar cookers
Reason (R): Concave mirror converges the light rays falling on it to a point
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 but R is true.
Answer:
A) Both A and R are true and R is the correct explanation of A.

Question 40.
Assertion (A): Higher is the refractive index of a medium or denser the medium, lesser is the velocity of light in that medium.
Reason (R): Refractive index is immersely proportional to velocity.
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 but R is true.
Answer:
A) Both A and R are true and R is the correct explanation of A.

Question 41.
Assertion (A): 1.33 is the absolute refractive index of water.
Reason (R): Air is optically denser than water.
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 but R is true.
Answer:
C) A is true but R is false.

Question 42.
An object is placed in front of a convex mirror. Its image is formed :
A) at a distance equal to the object distance in front of the mirror.
B) at twice the distance of the object in front of the mirror.
C) half the distance of the object in front of the mirror.
D) behind the mirror and it’s position varies according to the object distance.
Answer:
D) behind the mirror and it’s position varies according to the object distance.

Question 43.
For the diagram shown, according to the new Cartesian sign convention the magnification of the image formed will have the following specifications:

A) Sign – Positive, Value – Less than 1
B) Sign – Positive, Value – More than 1
C) Sign – Negative, Value – Less than 1
D) Sign – Negative, Value – More than 1
Answer:
B) Sign – Positive, Value – More than 1

Question 44.
Which of the following statements is not true in reference to the diagram shown below ?

A) Image formed is real.
B) Image formed is enlarged.
C) Image is formed at a distance equal to double the focal length.
D) Image formed is inverted.
Answer:
B) Image formed is enlarged.

Question 45.
An object of height 4 cm is kept at a distance of 30 cm from the pole of a diverging mirror. If the focal length of the mirror is 10 cm, the height of the image formed is
A) +3.0 cm
B) +2.5 cm
C) +1.0 cm
D) +0.75 cm
Answer:
B) +2.5 cm

Question 46.
A student obtains a sharp image of the distant window (W) of the school laboratory on the screen (S) using the given concave mirror (M) to determine its focal length, which of the following distances should he measure to get the focal length of the mirror.

A) MW
B) MS
C) SW
D) MW-MS
Answer:
B) MS

Question 47.
A ray of light starting from air passes through medium A of refractive index 1.50, enters medium B of refractive index 1.33 and finally enters medium C of refractive index 2.42. If this ray emerges out in air from C, then for which of the following pairs of media the bending of light is least ?
A) air – A
B) A – B
C) B – C
D) C – air
Answer:
B) A – B

Question 48.
A ray of light is incident as shown. If A, B and C are three different transparent media, then which among the following options is true for the given diagram?

A) ∠1 >∠4
B) ∠1<∠2
C) ∠3 =∠2
D) ∠3 >∠4
Answer:
C) ∠3 =∠2

Question 49.
In the diagram shown n₁, n₂ and n₃ are refractive indices of the media 1, 2 and 3 respectively. Which one of the following is true in this case?

A) n₁ = n₂
B) n₁>n₂
C) n₂>n₃
D) n₃>n₁
Answer:
B) n₁>n₂

Question 50.
Select from the following the best experimental set-up for tracing the path of a ray of light passing through a rectangular glass slab: ( )

A) P
B) Q
C) R
D) S
Answer:
D) S

Question 51.
A student traces the path of a ray of light through a rectangular glass slab for the different values of angle of incidence. He observes all possible precautions at each step of the experiment. At the end of the experiment, on analyzing the measurements, which of the following conclusions is he likely to draw?
A)∠i = ∠e <∠r
B) ∠i < ∠e <∠r
C) ∠i > ∠e >∠r
D) ∠i = ∠e >∠r
Answer:
D) ∠i = ∠e >∠r

Question 52.
A student wants to obtain magnified Image of an object AB as on a screen. Which one of the following arrangements shows the correct position of AB for him/her to be successful?

Answer:
(C)

Question 53.
Study the given ray diagrams and select the correct statement from the following:

A) Device X is a concave mirror and device Y is a convex lens, whose focal lengths are 20 cm and 25 cm respectively.
B) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 10 cm and 25 cm respectively.
C) Device X is a concave lens and device Y is a convex mirror, whose focal lengths are 20 cm and 25 cm respectively.
D) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 20 cm and 25 cm respectively.
Answer:
D) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 20 cm and 25 cm respectively.

Question 54.
A student used a device ( X ) to obtain/focus the image of a well illuminated distant building on a screen ( S ) as shown below in the diagram. Select the correct statement about the device (X).

A) This device is a concave lens of focal length 8 cm.
B) This device ¡s a convex mirror of focal length 8 cm.
C) This device is a convex lens of focal length 4 cm.
D) This device is a convex lens of focal length 8 cm.
Answer:
D) This device is a convex lens of focal length 8 cm.

Question 55.
A student has obtained a magnified image of a flame on a screen using a convex lens. To draw the corresponding ray diagram, to show the image formation, which of the following two rays whose paths after refraction are shown he should select?

A) I and II
B) II and III
C) III and IV
D) I and III
Answer:
D) I and III

Question 56.
When light is incident on a glass slab, the incident ray, refracted ray and the emergent ray are in three media, A, B and C. If n₁, n₂ and n₃ are the refractive indices of A, B and C respectively and the emergent ray is parallel to the incident ray, which of the following is true?
A) n₁<n₂ < n₃
B) n₁ > n₂ > n₃
C) n₁< n₂ = n₃
D) n₁ = n₃< n₂
Answer:
D) n₁ = n₃< n₂

Question 57.
Examine the given figure and state which of the following option is correct?
[One small box in the figure is equal to 1 cm]

A) The mirror has a focal length of -6 cm and will produce an image of magnification +1
B) The mirror has a focal length of -3 cm and will produce an image of magnification -1
C) The mirror has a focal length of -3 cm and will produce an image of magnification +1
D) The mirror has a focal length of -6 cm and will produce an image of magnification -1
Answer:
B) The mirror has a focal length of -3 cm and will produce an image of magnification -1

Question 58.
Which diagram shows image formation of an object on a screen by a converging lens?

Answer:
(C)

Question 59.
The angle of incidence from air to glass at the point O on the hemispherical glass slab is.
A) 45°
B) 0°
C) 90°
D) 180°
Answer:
B) 0°

Question 60.
If the power of a lens is -4.0D, then it means that kens is a
A) concave lens of focal length -50 m
B) convex lens of focal length +50 cm
C) concave lens of focal length -25 cm
D) convex lens of focal length -25 m
Answer:
C) concave lens of focal length -25 cm

Question 61.
In the adjacent diagram light is travelling through different media. It is noted by a scientist that ∠1= ∠3 = ∠4 but ∠2<∠1. Which of the following statement would be correct?
A) Medium 1 is the denser than medium 3 but it’s density is equal to medium 2
B) Medium 2 is the rarest medium.
C) Medium 3 is denser than medium 1
D) Medium 1 and 3 are essentially the same medium, but medium 2 is denser than 1 and 3.
Answer:
A) Medium 1 is the denser than medium 3 but it’s density is equal to medium 2

Question 62.
What is the correct pair for the type of mirror and the size of the image formed by a concave mirror when the object is placed at infinity ?
A) Concave mirror – Highly diminished, point-sized image
B) Concave mirror – Diminished image
C) Concave mirror – Highly enlarged image
D) Concave mirror – Same size image
Answer:
A) Concave mirror – Highly diminished, point-sized image

Question 63.
Select the odd one out.
A) Real image
B) Virtual image
C) Enlarged image
D) Inverted image
Answer:
C) Enlarged image

Question 64.
Assertion: When light passes through a denser medium, it bends towards the normal.
Reason: When light passes from a rarer medium to a denser medium, it slows down and bends towards the normal.
A) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
B) Both Assertion and Reason are true; but Reason is not the correct explanation of Assertion.
C) Assertion is true, but Reason is false.
D) Both Assertion and Reason are false.
Answer:
A) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Question 65.
Assertion : The angle of incidence is greater than the angle of refraction when light passes from a denser medium to a rarer medium.
Reason : The speed of light is greater in a denser medium than a rarer medium.
A) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
B) Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
C) Assertion is true, but Reason is false.
D) Both Assertion and Reason are false.
Answer:
B) Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.

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