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

A red light is used in a traffic signal because

  1. it is visible to people even with bad eyesight

  2. it is beautiful

  3. it has the longest wavelength and can be easily noticed from a long distance

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

Red color, due to its longer wavelength does not get scattered by the particles in the atmosphere and hence it is used as traffic light. 

Multiple choice

The clear sky looks blue because of

  1. reflection of light

  2. refraction of light

  3. deffraction of light

  4. dispersion of light
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The sky appears blue because of Rayleigh scattering, which is a form of light scattering where shorter wavelengths (blue) are scattered more strongly by atmospheric particles than longer wavelengths (red). While often categorized under scattering, it is frequently grouped with dispersion in general science contexts.

Multiple choice

Eyes with less rod cells would not be able to sense ________________.

  1. dim light

  2. bright light

  3. small objects

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

Yes, it is correct. Eyes contain rod cells and cone cells. Rod cells are the nerve cells that are sensitive against dim light. Eye can sense objects because of rod cells and if the rod cells are less than normal value, the eye would not be able to see in dim light.

Multiple choice

Tyndall effect in colloids is caused due to

  1. dispersion of light

  2. merging of light rays

  3. scattering of light

  4. convergence of light rays
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Tyndall effect is the effect of light scattering in many directions in colloidal dispersion, while showing no such effect in a true solution. This effect is used to determine whether a mixture is a true solution or a colloid.

Multiple choice

Aquatic photodiffraction is

  1. euphotic, disphotic and aphotic

  2. aphotic, euphotic and disphotic

  3. euphotic, aphotic and disphotic

  4. euphotic and disphotic only
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The euphotic zone is the layer closer to the surface that receives enough light for photosynthesis to occur. The disphotic zone is found just below the photic zone. The aphotic zone is the portion of a lake or ocean where there is little or no sunlight.

Multiple choice

The particles of suspension_________?

  1. can be seen with naked eye.

  2. cannot be seen with naked eye.

  3. cannot be seen through a microscope.

  4. can be seen through a microscope.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The particles of suspension can be seen with naked eyes.

Multiple choice

When a beam of light is passed through a true solution, the path of light is not visible because

  1. in a true solution, amount of particles is negligible

  2. in a true solution, there are large spaces between the particles

  3. in a true solution, the size of particles is very small

  4. true solutions absorb the light completely
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

True solutions are homogeneous mixtures in which the size of the particles is less than 1 nm in diameter. Because of the small size, the solute particles do not scatter a beam of light passing through the solution. Therefore, the path of light is not visible in a true solution.

Multiple choice

A ray is entering from one medium to another medium. Which of the following statements is true in this context?

  1. Frequency of rays doesn't change, but its wavelength changes.

  2. Frequency of rays changes, but its wavelength doesn't change.

  3. Phase and velocity of ray change but its wavelength doesn't change

  4. Phase and velocity of rays doesn't change, but its wavelength changes.

  5. Frequency, phase, velocity and wavelength; all change.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Frequency doesn't change, but the wavelength changes.