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

Coherent light is ...

  1. Light energy that is not "in phase"

  2. Light energy that is "in phase"

  3. Light energy that is "out of sync"

  4. White light that is "out of phase"
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Coherent light consists of waves that are in phase, meaning their peaks and troughs align perfectly. This spatial and temporal alignment is what allows laser beams to remain focused over long distances.

Multiple choice

What does LASER stand for?

  1. Light Amplification by Stimulated Emission of Radio-waves

  2. Light Augmented by Stimulated Emission of Radiation

  3. Light Augmented by Stimulated Emission of Radio-waves

  4. Light Amplification by Stimulated Emission of Radiation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

LASER is an acronym for Light Amplification by Stimulated Emission of Radiation. This describes the physical process by which the laser beam is generated.

Multiple choice evs option d: astrophysics moon the moon's path in the sky the moon

sky appears blue because of 

  1. Total Internal

  2. Scattering

  3. Refraction

  4. Total internal reflection
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sky appears blue because of Scattering.Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.


Therefore, B is correct option.

Multiple choice zoology adaptations to different ecosystems adaptations to aquatic habitat different ecosystem ecosystem

Aquatic photodiffraction produces zones, like

  1. Euphotic, disphotic and disaphotic

  2. Aphotic, euphotic and disphotic

  3. Euphotic, aphotic and disphotic

  4. Euphotic, disphotic and aphotic
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The photic zone or euphotic zone is the depth of the water in a lake or ocean, that is exposed to such intensity of light at which the rate of oxygen consumption, is equal to the rate of carbon dioxide production. It extends from the surface down to a depth where light intensity falls to one percent of that at the surface, called the euphotic depth. About 90% of all marine life lives in the euphotic zone.

The zone which extends from the base of the euphotic zone to about 200 metres is called as the disphotic zone. While there is some light, it is insufficient for photosynthesis. The euphotic zone together with the disphotic zone coincides with the epipelagic zone. The bottommost zone, below the euphotic zone, is called as the aphotic zone. Most deep ocean waters belong to this zone.

Multiple choice zoology adaptations to different ecosystems adaptations to aquatic habitat different ecosystem ecosystem

Aquatic photodiffraction produces zones

  1. Euphotic, disphotic and aphotic

  2. Aphotic, euphotic and disphotic

  3. Euphotic, aphotic and disphotic

  4. Disphotic, aphotic and euphotic
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Aquatic light penetration creates three distinct zones. The euphotic zone receives sufficient light for photosynthesis. The disphotic zone receives some light but insufficient for photosynthesis. The aphotic zone receives no sunlight at all. This order from surface to depth is fundamental to aquatic ecosystem structure.

Multiple choice evs magic with mirrors introduction to light and mirror image formation by plane mirror light : reflection and refraction from plane surface

It is necessary to illuminate the bottom of a well by reflected solar beam when the light is incident at an angle of $\alpha = {40}^{\circ}$ to the vertical. At what angle $\beta$ to the horizontal should a plane mirror be placed?

  1. ${70}^{\circ}$
  2. ${20}^{\circ}$
  3. ${50}^{\circ}$
  4. ${40}^{\circ}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The light is incident at 40 degrees to the vertical, so it makes an angle of 50 degrees with the horizontal. To reflect this light vertically downward, the mirror must bisect the angle between the incident ray and the vertical. The angle of the mirror to the horizontal is 70 degrees.

Multiple choice physics light : reflection and refraction from plane surface introduction to light and mirror magic with mirrors image formation by plane mirror principle of reversibility of path of light refractive index

A source of light lies on the angle bisector of two plane mirrors inclined at an angle $\theta$. The values of $\theta$, so that the light reflected from one mirror does not reach the other mirror will be

  1. $\theta \geq 120^0$
  2. $\theta \geq 90^0$
  3. $\theta \leq 120^0$
  4. $\theta < 30^0$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For the light reflected from one mirror not to reach the other, the angle of incidence on the second mirror must be such that it cannot be reflected. This occurs when the angle between the mirrors is 120 degrees or more.

Multiple choice physics light : reflection and refraction from plane surface introduction to light and mirror magic with mirrors image formation by plane mirror principle of reversibility of path of light refractive index

The angle between the incident and reflected rays is $90^o$. If the plane mirror is rotated by $10^o$ about O in the anti-clockwise direction in the plane perpendicular to the mirror, then the angle between the incident and reflected rays will be _______$^0$.

  1. 70

  2. 100

  3. 90

  4. 110

  5. 80
Reveal answer Fill a bubble to check yourself
A,D Correct answer
Explanation

If the plane mirror is rotated by 10 degrees about O in the anti-clockwise direction then the angle between the incident and reflected rays will be reduced by 20 degrees. So the angle between incident and reflected ray will be 70 degrees.
If the plane mirror is rotated by 10 degrees in clockwise direction, then the angle between the incident and reflected rays increases by 20 degrees and becomes 110 degrees.

Multiple choice physics light : reflection and refraction from plane surface introduction to light and mirror magic with mirrors image formation by plane mirror principle of reversibility of path of light refractive index

A ray of light making an angle $10^o$ with the horizontal is incident on a plane mirror making angle $\theta$ with the horizontal. What should be the value of $\theta$ so that the reflected ray goes vertically upward?

  1. $30^o$
  2. $40^o$
  3. $50^o$
  4. $60^o$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The situation is as shown in figure:
The reflected ray makes an angle, $100-\theta$ with the normal. This is also equal to $\theta$.
$\therefore 100-\theta=\theta$
$\Rightarrow \theta=50^o$
Multiple choice

Humans can produce a laser light. How bright can it get?

  1. as bright as the sun

  2. 100 times brighter than the sun

  3. as bright as a night light

  4. a million times brighter than the sun
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Focused laser light can be incredibly intense, and modern high-power lasers can be engineered to be a million times brighter than the surface of the sun. This is achieved by concentrating energy into a very small area and time frame.

Multiple choice botany photosynthesis action spectrum and absorption spectrum spectrum of electromagnetic radiation chloroplast and pigments of photosynthesis site of photosynthesis

The special features of spectrophotometer includes

  1. Spectral bandwidth

  2. Percentage of sample-transmission

  3. Logarithmic range of sample absorption

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In a spectrophotometer, the spectrometer produces the desired range of wavelength of light from a wide range of wavelengths. Transmittance (T) is the percentage of sample transmission and is defined as the fraction of light that passes through the sample. It is related to absorption by the expression 

Absorbance(A)= --logT=--logIt/Io, where It is the amount of light transmitted and Io is the amount of light incident on the cuvette solution. 
So, the correct answer is 'All of the above'

Multiple choice physics light and shadow formation of image by a pinhole camera pinhole camera shadow

Shadow formation is an example of :

  1. rectilinear propagation of light

  2. curvilinear propagation of light

  3. dispersion of light

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

Rayleigh Scattering is responsible for the formation of shadows which is phenomena of rectilinear propagation of light . Shadows are created when an object, animal or person blocks out a portion of a light source. Shadows form in the opposite direction of whatever is blocking that source.