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

Directions: Fill in the blank with the most appropriate of the given options.

Although thunder and lightning are produced at the same time, light waves travel faster _____, so we see the lightning before we hear the thunder.

  1. than sound waves do

  2. than sound waves are

  3. than are sound waves

  4. than sound waves ever have

  5. than sound waves are travelling
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When comparing two nouns with different verbs, the auxiliary 'do' is needed to avoid repetition. 'Light waves travel faster than sound waves do' is correct because 'do' substitutes for 'travel'. Other options either use incorrect forms ('are', 'have') or add unnecessary words.

Multiple choice

Read the given passage and fill blank (iv).

Directions: Complete this passage by selecting the most suitable option for the corresponding gap.

The white light that we see around us is a ______(i)_____mix of seven colours, that if divided and laid side by side for study make up a light spectrum. The seven colours are Violet, Indigo, Blue, Green, Yellow, Orange and Red. However, Blue, Green, and Red are the _____(ii)______ colours, because all the other colours may be got by mixing these. We think that a cherry is red because we see it_____(iii)_____ a red colour. However, if we applied a filter and ____(iv)_______the red part of the light from its source, then the cherry would appear black.

  1. allowed

  2. derived

  3. mixed

  4. blocked
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

'Block' is to prevent entry of something (here part of light).

Multiple choice

Read the given passage and fill blank (ii).

Directions: Complete this passage by selecting the most suitable option for the corresponding gap.

The white light that we see around us is a ______(i)_____mix of seven colours, that if divided and laid side by side for study make up a light spectrum. The seven colours are Violet, Indigo, Blue, Green, Yellow, Orange and Red. However, Blue, Green, and Red are the _____(ii)______ colours, because all the other colours may be got by mixing these. We think that a cherry is red because we see it_____(iii)_____ a red colour. However, if we applied a filter and ____(iv)_______the red part of the light from its source, then the cherry would appear black.

  1. main

  2. remaining

  3. only

  4. permanent
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The passage explains that Blue, Green, and Red are fundamental colors because all other colors can be created by mixing them. These are the 'main' or primary colors in the RGB color model. The sentence structure 'However, [X], [Y], and [Z] are the _____ colours, because all the other colours may be got by mixing these' requires 'main' to establish their fundamental nature before explaining why.

Multiple choice

Read the given passage and fill blank (i).

Directions: Complete this passage by selecting the most suitable option for the corresponding gap.

The white light that we see around us is a ______(i)_____mix of seven colours, that if divided and laid side by side for study make up a light spectrum. The seven colours are Violet, Indigo, Blue, Green, Yellow, Orange and Red. However, Blue, Green, and Red are the _____(ii)______ colours, because all the other colours may be got by mixing these. We think that a cherry is red because we see it_____(iii)_____ a red colour. However, if we applied a filter and ____(iv)_______the red part of the light from its source, then the cherry would appear black.

  1. jumbled

  2. untidy

  3. balanced

  4. chaotic
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

There is a balance. 'Jumbled' is mixed up; 'untidy' is not neat and clean; 'chaotic' is disordered condition.

Multiple choice

Read the given passage and fill blank (iii).

Directions: Complete this passage by selecting the most suitable option for the corresponding gap.

The white light that we see around us is a ______(i)_____mix of seven colours, that if divided and laid side by side for study make up a light spectrum. The seven colours are Violet, Indigo, Blue, Green, Yellow, Orange and Red. However, Blue, Green, and Red are the _____(ii)______ colours, because all the other colours may be got by mixing these. We think that a cherry is red because we see it_____(iii)_____ a red colour. However, if we applied a filter and ____(iv)_______the red part of the light from its source, then the cherry would appear black.

  1. concealing

  2. spreading

  3. having

  4. hiding
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The sentence 'We think that a cherry is red because we see it__(iii)__ a red colour' requires a verb that connects seeing with possession. 'Having' is the only grammatically correct option - 'we see it having a red colour' means we perceive the cherry as possessing red color. 'Concealing', 'spreading', and 'hiding' don't make logical sense in this context.

Multiple choice

In digital modulation, a positive voltage represents a 1 and a negative voltage represents a 0. For an optical fibre, the presence and absence of light is represented by 1 and 0 respectively. This scheme is known as __________.

  1. non-return-to-zero

  2. return-to-zero

  3. non-to-zero

  4. one-to-zero
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In digital modulation, a positive voltage represents a 1 and a negative voltage represents a 0. For an optical fibre, the presence and absence of light is represented by 1 and 0 respectively. This scheme is known as non-return-to-zero. This typical name is given for historical reason.

Multiple choice

Optical fibres typically include a transparent core surrounded by a transparent cladding material. Light is kept inside the core by

  1. reflection

  2. interference

  3. total internal reflection

  4. diffraction

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

Optical fibres typically include a transparent core surrounded by a transparent cladding material with a lower index of refraction. Light is kept in the core by total internal reflection. This causes the fibre to act as a waveguide.

Multiple choice

Consider the following statements:

  1. The purpose of choke in tube light is to increase the current. (2) Lightening in the sky is caused due to electric discharge produced by friction between clouds.

Which of the given statements is/are correct?

  1. Only (1)

  2. Only (2)

  3. Both (1) & (2)

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

Statement (1) is wrong. The purpose of choke in tube light is to increase the voltage momentarily. Statement (2) is correct. Lightening in the sky is caused due to electric discharge produced by friction between clouds.

Multiple choice

Birefrigerence is used in which microscopy technique?

  1. Polarised light microscopy

  2. Confocal scanning light microscopy

  3. Flourescence microscopy

  4. Phase contrast microscopy

  5. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Birefrigerence is an optical activity. An object manifest birefrigerence by appearing bright when placed between two polarising filters oriented with their respective plane of transmission perpendicular to one another.

Multiple choice

Statement incorrect regarding lighting and thunder is

  1. lighting and thunder are caused by the accumulation and separation of charges in the clouds

  2. damages to the building due to lighting can be reduced to a large extent by a lighting conductor

  3. lighting conductor has a set of metal spikes connected by thick metal strip to a large silver plate buried in earth

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Option (3) is incorrect as lighting conductor has a set of metal spikes connected by a thick metal strip to a large copper plate buried in the earth.