mcq on light

MCQ on Light (Optics) Test+Quiz

[MCQ-1] What is the relation between focal length (f) and radius of curvature (r) of a curve mirror?

A: f = 2r
B: f = r/2
C: f = r/3
D: f = 3r/2

Answer

f =2r

[MCQ-2] What is the focal length of a curve mirror is it has a radius of curvature is 40 cm.

A: 20 cm
B: 35 cm
C: 25 cm
D: 40 cm

Answer

20 cm

[MCQ-3] Which type of mirror used in the headlight of a motorcycle?

A: Concave mirror
B: Convex mirror
C: Flat mirror
D: none of the above

Answer

Concave mirror

[MCQ-4] Which type of mirror used in the dental clinic?

A: Concave mirror
B: Convex mirror
C: Flat mirror
D: None of the above

Answer

Concave mirror

[MCQ-5] If a beam of red light and a beam of violet light are incident at the same angle on the inclined surface of a prism from air medium and produce angles of refraction r and v respectively, which of the following is correct?

A: r = v
B: r > v
C: r = 1/v
D: r < v

Answer

D: r < v

[MCQ-6] A point source of light is placed at the centre of curvature of a concave mirror. The angle of deviation of the rays incident on the mirror from this source and reflected from it is

A: 0
B: 180 degrees
C: 90 degrees
D: 360 degrees

Answer

B: 180 degrees

[MCQ-7] What kind of mirror is this?

concave mirror
fig 1

A: Convex mirror
B: Concave mirror
C: Plano Concave
D: Concavo Convex

Answer

Concave mirror

[MCQ-8] In the above figure – 1, the point P represents —

A: Pole
B: Center of curvature
C: Focus point
D: None of these

Answer

Pole

[MCQ-9] In the above figure – 1, what the point f indicates?

A: Pole
B: Center of curvature
C: Focus point
D: None of these

Answer

Focus point

[MCQ-10] In the above figure – 1, the point C represents-

A: Pole
B: Center of curvature
C: Focus point
D: None of these

Answer

Center of Curvature

[MCQ-11] Which among the following figure is correct regarding the reflection of light by a concave mirror?

concave mirror mcq

A: Figure 1 is correct
B: Figure 2 is correct
C: Figure 3 is correct
D: None of the figure is correct

Answer

Figure 1 is correct

[MCQ-12] What kind of lense is the following figure given below?

A: Concave Lens
B: Plano-Concave Lens
C: Convex lens
D: Concevo-Convex Lens;

Answer

Convex Lens

[MCQ-13] Which of the following figure given below is correct?

light passing through convex lens

A: Figure 1 is correct
B: Figure 2 is correct
C: Figure 3 is correct
D: Figure 4 is correct

Answer

Figure 1 is correct

[MCQ-14] In case of refraction, if the angle of incidence and the angle of refraction are 45 degrees and 30 degrees respectively, then the angle of deviation is

A: 75 o
B: 15o
C: 7.5o
D: 37.5o

Answer

B: 15o

[MCQ-15] Which of the following has the highest wavelength?

A: X-Ray
B: Gamma ray
C: infrared ray
D: ultraviolet ray

Answer

Infrared ray

[MCQ-16] To produce a real and magnified image by a convex lens, where should the object be placed? [f= focus; u= distance of the object from the lens]

A: f < u < 2f
B: u < 2f
C: u > 2f
D: u > f

Answer

A: f < u < 2f

[MCQ-17] If a refractive index of a medium is μ, and the velocity of a light in free space is c, then the velocity of light of that medium is

A: μc
B: (c/μ)1/2
C: (μc)1/2
D: c/μ

Answer

D: c/μ

[MCQ-18] When the light is passing from rarer to a denser medium, which is the correct statement?

A: Incident angle is equal to refracted angle
B: Incident angle is greater than refracted angle
C: Incident angle is less than refracted angle
D: Can not be determined

Answer

B: Incident angle is greater than refracted angle

[MCQ-19] Which physical quantity is remain constant in case refraction?

A: Wavelength of light
B: Frequency of light
D: Amplitude
E: All of the above

Answer

B: Frequency of light

[MCQ-20] In case of refraction, when the light passes from rarer to a denser medium, if the angle of incident is 65o and angle of refraction is 25o, then the deviation of angle would be-

A: 65o
B: 25o
C: 40o
D: 30o

Answer

C: 40o

[MCQ-21] The deviation of light ray when refracted by a parallel glass slab is –

A: 90 o
B: 0o
C: 45o
D: 180o

Answer

B: 0o

[MCQ-22] An object is placed at a distance u from a convex lens, and its image is formed at a distance v. What will be the formula of lateral magnification (m)?

A: m = uv
B: m = u/v
C: m= v/u
D: m= (u/v)1/2

Answer

C: m= v/u

[MCQ-23] What is the relation between the radius of curvature and the focal length of a mirror?

A: f = 3/r
B: f = r/3
C: f = 2r
D: f= r/2

Answer

D: f= r/2

[MCQ-24] The refractive index of a medium with respect to vacuum is

A: Always greater than one
B: Always less than one
C: Equal to one
D: none of the above

Answer

B: Always less than one.

[MCQ-25] Which color has the maximum deviation when white color refracted through a prism?

A: Red
B: Violet
C: Green
D: Yellow

Answer

B: Violet

[MCQ-26] What will be the refractive index of a medium when the velocity of light is 2 × 108 m/s?

A: 1
B: 1.2
C: 1.5
D: 1.7

Answer

C: 1.5

[MCQ-27] Which among the following electromagnetic wave the frequency is maximum?

A: Infrared
B: Ultraviolet
C: X-ray
D: Gama Ray

Answer

D: Gama Ray

[MCQ-28] What type of image will be formed if an object is placed between f and 2f in front of a convex lens?

A: Real and enlarged upright
B: Real and diminished
C: Virtual, enlarged and upright
D: Real, enlarged, inverted

Answer

D: Real, enlarged, inverted

[MCQ-29] For White light which color has the maximum refractive index?

A: Red
B: Yellow
C: Orange
D: Violet

Answer

D: Violet

[MCQ-30] What will be the angle of refraction for a ray of light fall perpendicular to the interface of two mediums?

A: 90o
B:0o
C: 180o
D: 45o

Answer

B: 0o

[MCQ-31] What will be the refractive index of a medium if a light ray falls normally on it?

A: One
B: one half
C: 3/2
D: infinity

Answer

D: Infinity

[MCQ-32] Snell’s law is valid for

A: Reflection of light
B: Refraction of light
C: Both A and B
D: None of A and B

Answer

B: Refraction of light

[MCQ-33] Let ∠i = angle of incidence, ∠r = angle of refraction, and μ = refractive angle. The correct formula for Snell”s law is –

A: μ = sin∠i × sin∠r
B: μ = sin∠i × cos∠r
C: μ = (sin∠i)/(sin∠r)
D: μ = (sin∠r)/(sin∠i)

Answer

C: μ = sin∠i/sin∠r

[MCQ-34] The color of light depends on

A: Wavelength
B: Frequency
C: Amplitude
D: All of the above

Answer

B: Frequency

[MCQ-35] Between red and violet, which color has more frequency?

A: Red has more frequency than violet
B: Violet has more frequency than red
C: Red and violet has the same frequency
D: Can not say

Answer

B: Violet has more frequency than red

[MCQ-36] Between red and violet, which color has greater wavelength?

A: Red has a greater wavelength than violet.
B: Violet has a greater wavelength than red.
C: Red and violet have the same wavelength.
D: Can not say

Answer

A: Red has a greater wavelength than violet.

[MCQ-37] Let frequency = n, wavelength = λ, and the velocity of light is c. Which relation among the following is correct?

A: c = nλ
B: c = n/λ
C: c = λ/n
D: c = n2

Answer

A: c = nλ

[MCQ-38] For which of the following color does a lens has maximum focal length?

A: Red
B: Yellow
C: Green
D: Violet

Answer

A: Red

[MCQ-39] For an object placed at the focus of a convex lens the image will be formed at

A: Focus
B: Optical center
C: Infinity
D: Twice the length of focus

Answer

Infinity

[MCQ-40] A convex mirror is used

A: by a dentist
B: for shaving
C: as a review mirror of a vehicle
D: as a light reflector for obtaining a parallel beam of light

Answer

C

[MCQ-41] Choose whether the statement is true or false: Focal length of a lens depends on its surrounding medium.

A: true
B: false

Answer

True

[MCQ-42] To obtain parallel ray from a point light source we use

A: both convex lens and concave mirror
B: both convex lens and convex mirror
C: both concave lens and concave mirror
D: both concave lens and convex mirror

Answer

A: both convex lens and concave mirror

[MCQ-43] What is the type of image form on the retina of our eyes?

A: Real and upright
B: Virtual and upright
C: Real and inverted
D: Virtual and inverted

Answer

Real and inverted

[MCQ-44] Which color is used as danger sign?

A: Green
B: Brown
C: Orange
D: Red

Answer

Red

[MCQ-45] For danger sign, red color is used, because

A: Scattering of red color is less due to large wavelength
B: Scattering of red color is less due to small wavelength
C: Scattering of red color is greater due to large wavelength
D: Scattering of red color is greater due to small wavelenth

Answer

A: Scattering of red color is less due to large wavelength

[MCQ-46] 4 different mediums P, Q, R and S have refractive index 1.5, 1.4, 1.8, and 1.3 respectively. In which medium the light has the maximum speed?

A: P medium
B: Q medium
C: R medium
D: S medium

Answer

S medium

[MCQ-47] Let μr and μv are the refractive indexes of a medium of red and violet color respectively. Then

A: μr > μv
B: μr < μv
C: μr = μv
D: None of the above

Answer

B: μr < μv

[MCQ-48] Focal length of a convex lens is 15 cm. For which distance an object is placed so that the lens acts as a magnifying glass?

A: Between 15 cm and 30 cm
B: Less than 15 cm
C: Greater than 30 cm
D: Exactly at 30 cm

Answer

B: Less than 15 cm

[MCQ-49] = deviation of prism, i1 = angle of incidence, i2 = angle of refraction of a prism. Which formula is correct?

A: = i1 + i2 − A
B: = i1 + i2 + A
C: = i1 − i2 + A
D: = (i1 + i2)/A

Answer

A

[MCQ-50] Deviation of light passing through the center of lens is

A: 0°
B: 45°
C: 90°
D: 180°

Answer

A: 0°

[MCQ-51] The split of white light into 7 colors by prism is known as

A: Diffraction
B: Dispersion
C: scattering
D: Polarization

Answer

B: Dispersion

[MCQ-52] What is the speed of light in free space?

A: 3.5 ×108 m/s
B: 3 ×108 m/s
C: 3 ×109 m/s
D: 3.5 ×109 m/s

Answer

B: 3 ×108 m/s

These are the most common MCQs from light you need to practice. You may download the set of these questions with answers as pdf format.

Note: All the MCQs on light are important for any competitive examination. These multiple choice question answers from light (optics) are very useful for class 9 and class 10.