Light MCQ for Competitive Exams

5/5 - (5 votes)

Light MCQ for Competitive Exams. We covered all the Physics Light MCQ for Competitive Exams in this post for free so that you can practice well for the exam.

Install our MCQTUBE Android app from the Google Play Store and prepare for any competitive government exams for free.

These types of competitive MCQs appear in the exams like SSC, Railways, Defence, CDS, NDA, State PSC & CSE Exams, etc.

We created all the competitive exam MCQs into several small posts on our website for your convenience.

Join Telegram Group and Get FREE Alerts! Join Now

Join WhatsApp Group For FREE Alerts! Join Now

You will get their respective links in the related posts section provided below.

Related Posts:

Questions hide

MCQ on Light for Competitive Exams

The position, relative size and nature of the image formed by a concave lens for an object placed at infinity are respectively

(a) at focus, diminished and virtual

(b) at focus, diminished and real

(c) between focus and optical centre, diminished and virtual

(d) between focus and optical centre, magnified and real

Option a – at focus, diminished and virtual

The upper and lower portions in a common type of bi-focal lenses are respectively

(a) concave and convex

(b) convex and concave

(c) both concave of different focal lengths

(d) both convex of different focal lengths

Option a – concave and convex

In the phenomenon of dispersion of light, the light wave of the shortest wavelength is

(a) accelerated and refracted the most

(b) slowed down and refracted the most

(c) accelerated and refracted the least

(d) slowed down and refracted the least

Option a – accelerated and refracted the most

Wavelengths of which of the following colour of the visible spectrum of light are maximally absorbed by green plants?

(a) Green and Yellow

(b) Red and Blue

(c) Green and Red

(d) Blue and Yellow

Option b – Red and Blue

Consider the following statements 1. A person with myopia can see distant objects distinctly but cannot see nearby objects clearly. 2. A person with hypermetropia cannot see distant objects clearly. 3. A person with presbyopia can see nearby objects without corrective glasses. Which of the statements given above is/are not correct?

(a) 1, 2 and 3

(b) 1 and 2

(c) 1 and 3

(d) Only 3

Option a – 1, 2 and 3

Which one of the following statements is not correct?

(a) The longest wavelength of the light visible human eye is about 700 mm

(b) The shortest wavelength of light visible to the human eye is about 400 mm

(c) The wavelength of gamma rays is longer than that of X-rays

(d) The ability of a telescope to form a separable image of close objects is called its resolving power

Option c – The wavelength of gamma rays is longer than that of X-rays

If the image of an object, formed by a concave mirror is virtual, erect and magnified, then the object is placed

(a) the principal focus

(b) at the centre of curvature

(c) beyond the centre of curvature

(d) between the pole of the mirror and the principal focus

Option d – between the pole of the mirror and the principal focus

The dispersion process forms a spectrum due to white light on the prism. The light wave with the shortest wavelength falls a

(a) refracts the most

(b) does not change the path

(c) refracts the least

(d) is reflected by the side of the prism

Option a – refracts the most

A ray of white light strikes the surface of an object. If all the colours are reflected the surface would appear

(a) black

(b) white

(c) grey

(d) opaque

Option b – white

A 10 mm long awl pin is placed vertically in front of a concave mirror. A 5 mm long image of the awl pin is formed at 30 cm in front of the mirror. The focal length of this mirror is

(a) -30 cm

(b) – 20 cm

(c) – 40 cm

(d) – 60 cm

Option b – – 20 cm

The angle of incidence i and refraction r are equal in a transparent slab when the value of i is

(a) 0º

(b) 45°

(c) 90°

(d) depends on the material of the slab

Option a – 0º

The refractive index of a transparent medium is greater than one because

(a) Speed of light in vacuum

(b) speed of light in a transparent medium

(c) Speed flight in vacuum=speed of light in a transparent medium

(d) Frequency of light wave changes when it moves from rarer to denser medium

Option b – speed of light in a transparent medium

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

Option b – B

Light from the Sun falling on a convex lens will converge at a point called

(a) centre of curvature

(b) focus

(c) the radius of curvature

(d) optical centre

Option b – focus

Which of the following statements is/are true?

(a) A convex lens has 4 dioptre power having a focal length of 0.25 m

(b) A convex lens has -4 dioptre power having a focal length of 0.25 m

(c) A concave lens has 4 dioptre power having a focal length of 0.25 m

(d) A concave lens has – 4 dioptres having a focal 0.25 m

Option a – A convex lens has 4 dioptre power having a focal length of 0.25 m

Magnification produced by a rearview 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.

Option a – is less than one

As the sunlight passes through the atmosphere, the rays are scattered by tiny particles of dust, pollen, soot and other minute particulate matter present there. However, when we look up, the sky appears blue during mid-day because

(a) blue light is scattered most

(b) blue light is absorbed most

(c) blue light is reflected most

(d) ultraviolet and yellow components of sunlight combine

Option a – blue light is scattered most

A lens has a power of +2.0 Dioptre. Which one of the following statements about the lens is true?

(a) The lens is concave and has a focal length of 0.5 metres

(b) The lens is convex and has a focal length of 2.0 metre

(c) The lens is convex and has a focal length of 0.5 metres

(d) The lens is concave and has a focal length of 2.0 metre

Option c – The lens is convex and has a focal length of 0.5 metres

Which of the following lenses will bend the light rays through the largest angle?

(a) A lens with power +2.0 D

(b) Lens with power +2.5 D

(c) Lens with power-1.5 D

(d) Lens with power-2.0 D

Option b – Lens with power +2.5 D

The nature of the image formed by a 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

Option c – real, inverted and enlarged

The nature of the image formed by a convex mirror when the object’s distance from the mirror is less than the distance between the pole and focal point (F) of the mirror would be

(a) real, inverted and diminished in size

(b) real, inverted and enlarged in size

(c) virtual, upright and diminished in size

(d) virtual, upright and enlarged in size

Option c – virtual, upright and diminished in size

If a man’s face is 25 cm in front of a concave shaving mirror producing an erect image 1.5 times the size of his face, the focal length of the mirror would be

(a) 75 cm

(b) 25 cm

(c) 15 cm

(d) 60 cm

Option a – 75 cm

As light travels from a rarer to a denser medium it will have

(a) increased velocity

(b) decreased velocity

(c) decreased wavelength

(d) both (b) and (c)

Option d – both (b) and (c)

Which of the following statements is NOT correct regarding the travel of sound waves?

(a) Sound waves can travel through water

(b) Sound waves can travel through the air

(c) Sound waves can travel through steel

Join Telegram Group and Get FREE Alerts! Join Now

Join WhatsApp Group For FREE Alerts! Join Now

(d) Sound waves can travel through a vacuum

Option d – Sound waves can travel through a vacuum

Light of uniform intensity impinges perpendicularly on a totally reflecting surface. If the area of the surface is halved, the radiation force on it will become

(a) double

(b) half

(c) four times

(d) one fourth

Option b – half

The width of diffraction fringes varies :

(A) directly as the distance between the slit and the screen

(B) inversely as the wavelength

(C) directly as the width of the slit

(D) independent of the distance between the slit and the screen

Option a – directly as the distance between the slit and the screen

Scattering of light is a direct consequence of

(A) diffraction

(B) interference

(C) dispersions

(D) reflection

Option a – diffraction

While both light and sound show wave character, diffraction is much harder to observe in light. This is because

(A) light does not require a medium

(B) the wavelength of light is far smaller

(C) waves of light are transverse

(D) the speed of light is far greater.

Option b – the wavelength of light is far smaller

The compact disc shows color in white light due to the:

(A) interference

(B) polarization

(C) diffraction

(D) scattering

Option c – diffraction

The bending of light around corners of an obstacle is called :

(A) dispersion

(B) refraction

(C) deviation

(D) diffraction

Option d – diffraction

A diffraction pattern is obtained using red light. Which of the following happens if the red light is replaced by blue light?

(A) There is no change

(B) Diffraction bands become narrower and more crowded

(C) Diffraction bands become broader and farther

(D) Bands disappear

Option b – Diffraction bands become narrower and more crowded

A parallel beam of light is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of the slit is :

(A) 2π

(B) π

(C) π/2

(D) π/3

Option a – 2π

Diffraction of light was discovered by :

(A) Young

(B) Hertz

(C) Grimaldi

(D) Malus

Option c – Grimaldi

The fringe pattern observed in young’s double slit experiment is :

(A) diffraction pattern

(B) interference pattern

(C) a combination of diffraction and interference pattern

(D) neither interference nor diffraction pattern

Option c – a combination of diffraction and interference pattern

Yellow light is used in a single slit diffraction experiment with a slit width of 0.6 mm. If the yellow light is replaced by X-rays, then the observed pattern will reveal :

(A) that the central maximum is narrower

(B) more fringes will be seen

(C) less number of fringes will be seen

(D) no diffraction pattern will be seen

Option d – no diffraction pattern will be seen

The condition for observing Fraunhofer diffraction from a single slit is that the light wavefront incident on the slit should be :

(A) spherical

(B) plane

(C) cylindrical

(D) elliptical

Option b – plane

The condition for observing Fresnel’s diffraction from a single slit is that the light wavefront incident on the slit should be :

(A) spherical

(B) plane

(C) cylindrical

(D) (A) or (C)

Option d – (A) or (C)

Sunlight filtering through tree leaves often makes circular patches on the ground because

(A) the sun is round

(B) light is transverse in nature

(C) the space through which light penetrates is round

(D) diffraction effects

Option d – diffraction effects

From Brewster’s law for polarization, it follows that the angle of polarization depends upon

(A) the wavelength of light

(B) the plane of vibration’s orientation

(C) the plane of polarization orientation

(D) all of these

Option a – the wavelength of light

An unpolarised beam of transverse waves is one whose vibrations :

(A) are confined to a single plane

(B) occur in all directions

(C) occur in all directions perpendicular to their direction of motion

(D) has not passed through a polarised disk

Option c – occur in all directions perpendicular to their direction of motion

In the propagation of electromagnetic waves, the angle between the direction of propagation and the plane of polarization is :

(A) 0°

(B) 45°

(C) 90°

(D) 120°

Option a – 0°

Which of the following cannot be polarized?

(A) Radio waves

(B) Ultraviolet rays

(C) X-ray

(D) Ultrasonic waves

Option d – Ultrasonic waves

Longitudinal waves do not exhibit :

(A) diffraction

(B) reflection

(C) polarization

(D) refraction

Option c – polarization

Two polarizing plates have polarizing directions parallel so as to transmit maximum intensity of light. Through what angle must either plate be turned if the intensities of the transmitted beam are to drop by one-third that of the polarised beam?

(A) 54° 44′

(B) 125° 16′

(C) Both (A) and (B)

(D) 60°

Option c – Both (A) and (B)

A ray of light falls on a transparent glass plate, part of it is reflected and part is refracted. The reflected and refracted rays can be perpendicular to each other for :

(A) No angle of incidence

(B) Angle of incidence 90°

(C) More than one angle of incidence

(D) Only one angle of incidence

Option d – Only one angle of incidence

Which of the following properties exhibit that light waves are transverse in nature? :

(A) interference

(B) diffraction

(C) polarization

(D) all of these

Option c – polarization

The fact that light is a transverse wave phenomenon derives its evidential support from the observation that :

(A) light is a wave motion

(B) light is characterized by interference

(C) light shows polarizing effects

(D) light can be diffracted

Option c – light shows polarizing effects

The phenomenon which does not take place in a sound wave is :

(A) polarization

(B) scattering

(C) interference

(D) diffraction

Option a – polarization

When a plane polarised light is passed through an analyzer and the analyzer is rotated through 90°, the intensity of emerging light :

(A) varies between maximum and zero

(B) varies between maximum and minimum

(C) becomes zero

(D) does not vary

Option a – varies between maximum and zero

The oscillating electric and magnetic vectors of an electromagnetic wave are oriented along

(A) the same direction but differ in phase by 90°

(B) the same direction and are in phase

(C) mutually perpendicular directions and are in phase

(D) mutually perpendicular directions and differ in phase by 90°

Option c – mutually perpendicular directions and are in phase

We covered all the light MCQ for competitive exams above in this post for free so that you can practice well for the exam.

Check out the latest MCQ content by visiting our mcqtube website homepage.

Also, check out:

Join Telegram Group and Get FREE Alerts! Join Now

Join WhatsApp Group For FREE Alerts! Join Now

Hello, I am the admin of mcqtube.com website. I am a blogger and app developer. Thanks.

Leave a Comment

Sticky Bottom Popup