Tag: physics

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Multiple choice physics reflection of light and shadow terms related with reflection terms related to reflection of light laws of reflection

No matter how far you stand from a mirror, your image always appears erect. Then the mirror among the following is likely to be:

  1. a plane mirror

  2. a concave mirror

  3. any type of mirror

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

If the image always appears erect, then the mirror is either plane or convex. So, on the basis of the given options, the mirror is likely to be a plane mirror.

Multiple choice physics reflection of light and shadow terms related with reflection terms related to reflection of light laws of reflection

Fill in the blanks to complete the following sentences:


i) A ray travelling towards the mirror is the ______.
ii) Angle between reflected ray and normal is the ___.
iii) The angle between reflecting surface and the reflected ray is the ______.

  1. i-incident ray ,ii-angle of reflection ,iii-glancing angle of reflection

  2. i-normal ray ,ii-glancing angle of reflection ,iii-angle of incidence

  3. i-reflected ray ,ii glancing angle of incidence ,iii-glancing angle of reflection

  4. i-reflected ray ,ii-angle of incidence ,iii- angle of reflection
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to definition, 
i) A ray from the object, travelling towards the mirror is the incident ray.
ii) Angle between reflected ray and normal is the angle of reflection.
iii) The angle between reflecting surface and the reflected ray is known as the glancing angle of reflection.

Multiple choice physics reflection of light and shadow terms related with reflection terms related to reflection of light laws of reflection
The ray which bounces off the surface of the mirror when the incident ray strikes the mirror is known as ________.  The point at which incident ray meets the mirror is called the _________.

  1. normal ray, point of reflection

  2. reflected ray, point of refraction

  3. reflected ray, point of incidence

  4. diffracted ray, point of diffraction
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to definition of reflected ray and point of incidence, the ray which bounces off the surface of the mirror when the incident ray strikes the mirror is known as the reflected ray. The point at which incident ray meets the mirror is called the point of incidence.

Multiple choice physics reflection of light and shadow terms related with reflection terms related to reflection of light laws of reflection

Fill in the blank:

When angle of incidence increases, glancing angle of incidence ________.

  1. decreases

  2. increases

  3. remains same

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

Angle of incidence $+$ Glancing angle of incidence $=90^0$

So, Glancing angle of incidence $=90^0 -$ Angle of incidence
This means, when angle of incidence increases, glancing angle of incidence decreases,

Multiple choice physics reflection of light and shadow terms related with reflection terms related to reflection of light laws of reflection

Fill in the blank:

When the angle of incidence increases, glancing angle of reflection _______.

  1. increases

  2. remains same

  3. decreases

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

Angle of incidence $+$ glancing angle of incidence $=90^0$

So, glancing angle of incidence $=90^0 -$ angle of incidence
Now, glancing angle of incidence $=$ glancing angle of reflection
Therefore, glancing angle of reflection $=90^0 -$ angle of incidence
This means, when angle of incidence increases, glancing angle of reflection decreases,

Multiple choice physics reflection of light and shadow terms related with reflection terms related to reflection of light laws of reflection

Bouncing of light into the same medium, from which the light ray is incident, is termed as

  1. Refraction

  2. Diffraction

  3. Reflection

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

$ \bf{Refraction} $ of light is the phenomenon of bending of light or change in the direction of light, when it passes obliquely from one transparent medium to another.

$ \bf{Diffraction} $ is the phenomenon of bending of light waves around the corners of an obstacle or aperture, placed in the path of light beam.

$ \bf{Reflection} $ is the phenomenon in which light rays on striking a polished surface(such as a mirror) bounce back or are sent back into the same medium. 

$\bf{Scattering} $ is the phenomenon by which a beam of light is redirected or deflected in many different directions when it passes through an imperfect medium due to the interaction with the particles of the medium.

Hence, the correct answer is OPTION C. 

Multiple choice physics reflection of light and shadow terms related with reflection terms related to reflection of light laws of reflection

Reflection can occur on

  1. Transparent surfaces

  2. Translucent surfaces

  3. Opaque surfaces

  4. B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Objects which allow the light to pass through them completely without any obstruction are called $ \bf{transparent} $ objects.
Objects which allow the light to pass through them partially are called $ \bf{translucent} $ objects.
Objects which do not allow the light to pass through them are called $\bf{opaque} $ objects.

Since, transparent objects allow light to pass through them completely, no reflection can occur on them. 

Reflection occurs on translucent surfaces because they reflect a certain amount of light while allowing a certain amount of light to be transmitted. Reflection occurs perfectly on Opaque surfaces because they reflect all the light that falls on them without allowing any light to pass through them.

Hence, the correct answer is OPTION D.
Multiple choice physics reflection of light and shadow terms related with reflection terms related to reflection of light laws of reflection

Which of the following is the main reason of Opacity of light waves.

  1. reflection

  2. absorption

  3. refraction

  4. diffusion

  5. transmission
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Objects are visible to the eye when light strikes the surface and reflects back itself into the eye. Opaque objects show this phenomenon.

However in the transparent objects, the incident light on their surface gets transmitted, hence does not reflect back to eye and appear transparent.

Multiple choice physics reflection of light and shadow terms related with reflection terms related to reflection of light laws of reflection

A ray of light striking a plane mirror at an angle of 35 degrees with the normal.

Find out the angle of reflection with normal.

  1. 35 degrees.

  2. 55 degrees.

  3. 10 degrees

  4. 90 degrees

  5. 125 degrees
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Angle of incidence    $i = 35$ degrees

According to Snell's law of reflection, the angle of incidence is equal to the angle of reflection.
$\implies$ Angle of reflection      $r = i = 35$  degrees

Multiple choice physics reflection of light and shadow terms related with reflection terms related to reflection of light laws of reflection

When a light ray falls on a perfectly reflective mirror at an angle. Identify which of the following statement is true about the ray?

  1. The frequency of the light ray changes

  2. The wavelength of the light ray changes

  3. The velocity of the light ray changes

  4. The period of the light ray changes

  5. The direction of motion of the light ray changes
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

When a light ray falls on a perfectly reflective mirror at some angle, then only the direction of the light rays changes such that the angle of incidence is equal to the angle of reflection but the frequency, wavelength, time period and the velocity of the light remain constant.

Thus option E is correct.