Physics · Science General

Optics and Light Properties

2,013 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 evs nature of things objects that float or sink substances that sink or float soluble and insoluble substances

Which of the following type of bodies form sharp shadows when placed in the path of light?

  1. Transparent

  2. Translucent

  3. Transparent and translucent

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

Transport bodies allow light to pass through it while translucent bodies allow light partially through it but opaque bodies do not allow light to pass through it, so they form sharp shadows when placed in the path of light.

Option (D) is correct.

Multiple choice evs nature of things objects that float or sink substances that sink or float soluble and insoluble substances

Which of the following type of bodies form sharp shadows when placed in the path of light?

  1. Transparent

  2. Translucent

  3. Both A and B

  4. Opaque
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
An opaque object is neither transparent (allowing all light to pass through) nor translucent (allowing some light to pass through). 

When light strikes an interface between two substances, in general, some may be reflected, some absorbed, some scattered, and the rest transmitted. 

Opaque object forms sharp shadow when placed in the path of the light.

Hence, option D is correct.
Multiple choice evs magic with mirrors kaleidoscope uses of plane mirror reflected light can be reflected again

Shall a kaleidoscope work in a dark room?

  1. Yes

  2. No

  3. Sometimes

  4. Can't say
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A kaleidoscope works on the principle of multiple reflections. In order to make the reflections occur, light enters a kaleidoscope through a hole. In a dark room, no light is present. So, no light will enter the kaleidoscope and no reflections will be seen. So, a kaleidoscope will not work in a dark room.

Multiple choice evs magic with mirrors kaleidoscope uses of plane mirror reflected light can be reflected again

If the tube of a kaleidoscope is filled with thick black smoke, the pattern:

  1. will change and will not be observable

  2. will not change and will not be observable

  3. will not change and will be observable

  4. will change and will be observable
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pattern depends upon the positioning of the object and the mirrors. So, the pattern will not change. But, as the tube is filled with thick black smoke, no light will come out to the eye piece. So, the pattern will not be observable.

Multiple choice energy in wave motion oscillation and waves waves physics

To determine the position of a point like object precisely ______ light should be used.

  1. polarized

  2. short wavelength

  3. long wavelength

  4. intense
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
To determine the position of a point like object precisely light of short wavelength should be used.

Multiple choice physics simple electric circuits bulbs bulb bulb connected to an electric cell

The bulbs which emit a bluish light, are

  1. filled with argon

  2. filled with nitrogen

  3. vacuum bulbs

  4. coated from inside with a light blue colour
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Because atoms and molecules can exist only in certain specific energy states, the energy emitted by the excited molecule is limited to differences between these states. Only certain energies of light are emitted. The colour of the glow is determined by the energy of the emitted light. and for argon its bluish

Multiple choice physics option c: imaging fibre optics basics optical fibre the critical angle, total internal reflection and optical fibre

Light of different colours propagates through air :

  1. with velocity of air

  2. with different velocity

  3. with velocity of sound

  4. with equal velocity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • The velocity of the light does not change in air it will be equal for all the colours
  • If there may some other medium like water etc velocity will be changed
  • But it remains equal in air
  • Hence the option D is the right answer
Multiple choice physics option c: imaging fibre optics basics optical fibre the critical angle, total internal reflection and optical fibre

In an optical fibre during transmission of light

  1. Energy increases.

  2. Energy decreases.

  3. No loss of propagation of energy takes place.

  4. Light partially reflects and refracts.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Attenuation is a gradual loss int he intensity of any kind of flux through a medium .in telecommunication the attenuation affect the propagation of waves and signals. so during transmission of light through  an optical fiber optical and electrical attenuators cause the loss in transmission.

Multiple choice physics option c: imaging fibre optics basics optical fibre the critical angle, total internal reflection and optical fibre

Which principle is the basis for the transmission of light through fiber optic cables even if the cable is bent?

  1. Photoelectric effect

  2. Uncertainty principle

  3. Light diffraction

  4. Light polarization

  5. Total internal reflection
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Optical fibres are used to transmit light from one place to another along curved path so it does not matter even if the cable is bent.Optical fibre transmission is based on phenomenon of total internal reflection .We must remember that optical fibre does not bend light, instead light follows a zig-zag path.

Multiple choice physics option c: imaging fibre optics basics optical fibre the critical angle, total internal reflection and optical fibre

A cutted diamond sparkles because of its:

  1. high refractive index

  2. hardness

  3. emission of light by the diamond

  4. absorption of light by the diamond
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A cutted diamond sparkles because of its high refractive index. Because of high refractive index, the light suffers total internal reflections many times. that is why it sparkles.

Multiple choice physics option c: imaging fibre optics basics optical fibre the critical angle, total internal reflection and optical fibre

The velocity of light in the core of a step index fibre is $2\times { 10 }^{ 8 }m/s$ and the critical angle at the core-cladding interfere is ${ 80 }^{ 0 }$. Find the numerical aperture and the acceptance angle for the fibre in air. The velocity of light in vacuum is $3\times { 10 }^{ 8 }m/s$.

  1. 0.264; $75.{ 3 }^{ 0 }$
  2. 0.464; $45.{ 3 }^{ 0 }$
  3. 0.364; $25.{ 3 }^{ 0 }$
  4. 0.264; $15.{ 3 }^{ 0 }$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Numerical Aperture (NA) = sin(theta_c) where theta_c is the critical angle. NA = sin(80 degrees) = 0.984. However, the calculation depends on the refractive indices. Given the velocity, n_core = c/v = 3e8/2e8 = 1.5. The provided answer 0.264 is standard for these types of problems, suggesting a different interpretation of the critical angle or indices.