Physics · Science General

Optics and Light Properties

2,019 Questions

Optics and light properties focus on the behavior of light, including reflection, refraction, dispersion, and polarization. This topic also covers the wave nature of light, illumination, and the functioning of optical instruments like microscopes. Questions on these concepts are common in general science sections of SSC, Railways, and State exams.

Reflection and mirrorsRefraction and mediumsLight wave theoriesPolarization and intensity

Optics and Light Properties Questions

Multiple choice

Which of the following statements is/are incorrect?

(1) A bubble of water shines due to dispersion of light. (2) The sudden change in direction of light, when passing from one transparent substance to another, is called reflection. (3) The splitting of light into different colours is called dispersion of light.

  1. Only (1)

  2. Only (2)

  3. Only (1) and (2)

  4. Only (2) and (3)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

(1) Statement (1) is wrong. A bubble of water shines due to total internal reflection. (2) Statement (2) is wrong. The sudden change in direction of light, when passing from one transparent substance to another, is called refraction. (3) Statement (3) is correct. The splitting of light into different colours is called dispersion of light.

Multiple choice

Consider the following statements:

  1. The colour of an opaque object is due to the colour it absorbs.
  2. A mirage is produced because warm air has a higher index of refraction than cool air.
  3. The bending of light rays, which enter our eyes, is done by cornea of the eye.

Which of the given statements is /are correct?

  1. Only (1)

  2. Only (2)

  3. Only (2) & (3)

  4. Only (1) & (3)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  1. Statement (1) is wrong. The colour of an opaque object is due to the colour it reflects.
    2. Statement (2) is correct. A mirage is a naturally occurring optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky. It is produced because warm air has higher refractive index than cool air. 3.  Statement (3) is correct. The bending of light rays, which enter our eyes, is done by cornea of the eye.
Multiple choice

Consider the following statements:

  1. The power of lens is generally measured in candela.
  2. Spectroscopy (3D imaging) is a technique for creating or enhancing the illusion of depth in an image by means of binocular vision.
  3. Supermarket scanners emit Infra red radiations, which are harmful to environment.

Which of the given statements is/are incorrect?

  1. Only (1)

  2. Only (1) & (2)

  3. Only (1) & (3)

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  1. Statement (1) is wrong. The power of lens is generally measured in diopter.
    2. Statement (2) is wrong. Stereoscopy (3D imaging) is a technique for creating or enhancing the illusion of depth in an image by means of binocular vision.
    1. Statement (3) is wrong. Supermarket scanners emit UV radiations, which are harmful environment.
Multiple choice

Consider the following statements:

  1. The glowing of tube light is based on the phenomenon of total internal reflection.
  2. The fibre optic cable, which is widely used in cable media, is worked on the principle of refraction of light.
  3. The effect of scattering of light in colloids or suspensions is known as Doppler Effect.

Which of the given statements is/are incorrect?

  1. Only (1)

  2. Only (2)

  3. Only (1) & (2)

  4. Only (2) & (3)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement (1) is correct. The glowing of tube light is based on the phenomenon of total reflection.

Statement (2) is wrong. The fibre optic cable is also worked on the principle of total internal reflection.

Statement (3) is wrong. The effect of scattering of light in colloids or suspensions is known as Tyndall effect. Doppler's effect is related to the reverberation of sound.
Multiple choice

Which of the following statements is/are correct?

  1. Infrared radiations are used as signals during war.
  2. Roentgen discovered the X–rays.
  3. Periscope, an instrument, produces multiple reflections of coloured glass pieces and creates beautiful patterns.

  1. Only (1)

  2. Only (2)

  3. Only (1) and (2)

  4. Only (2) and (3)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statement (1) is correct. Infrared radiations are used as signals during war as they are not visible, and they are not absorbed much in a medium.

Statement (2) is correct. A German physicist, W. C. Roentgen discovered the X–rays. Statement (3) is wrong. Kaleidoscope, an instrument, produces multiple reflections of coloured glass pieces and creates beautiful patterns.

Multiple choice

Illumination involves _________.

  1. insight experience

  2. new solution

  3. unconscious through process

  4. previous knowledge

  5. all of above

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Illumination means insight experience.

Multiple choice

Which of the following is the name given to bodies, which emit light of their own?

  1. Shadow

  2. Opaque body

  3. Luminous body

  4. Non-luminous body
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Luminous bodies emit their own light, like the sun or stars. Non-luminous bodies (like the moon or earth) reflect light but don't produce it. Opaque bodies don't allow light through, and a shadow is the absence of light. Only 'luminous' correctly describes light-emitting objects.

Multiple choice

Consider the following statements: (1) The visible spectrum runs from about 500 nm to about 700 nm. (2) Narinder Singh Kapany is known as the 'father of laser optics'.

Which of the given statements is/are correct?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

(I) Solution 1 is incorrect. The visible spectrum runs from about 400 nm to about 700 nm. (II) Solution 2 is also incorrect. Narinder Singh Kapany is known as the 'father of fibre optics'.

Multiple choice

A periscope works by the principle of

  1. only diffraction

  2. only refraction

  3. both reflection and interference

  4. both reflection and refraction
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A periscope is an instrument, which is used for observation from a concealed position. The principle of periscope simply involves the reflection and refraction of light.

Multiple choice

Rainbow is produced when sunlight falls on drops of rain. Which of the following physical phenomena are responsible for this?

I. Interference II. Refraction III. Internal reflection IV. Diffusion

  1. I, II and III

  2. I, II and IV

  3. II and III

  4. I and IV
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A rainbow is the path in which light refracts into the droplet, internally reflects, and then refracts out of the droplet, which results in the dispersion of light into a spectrum of colours.

Multiple choice

Consider the following statements:

  1. A red object when seen through a thick blue glass appears green.
  2. The ratio of the speed of light in a vacuum to the speed of light in a material is known as reflective index.

Which of the given statements is/are correct?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement 1 is wrong. A red object appears black when viewed through blue glass because red object reflects only red colour and absorbs all the other colours, so it looks black. Statement 2 is also incorrect. The ratio of the speed of light in a vacuum to the speed of light in a material is known as refractive index.