Physics

Light and Mirrors

454 Questions

Light and mirrors questions cover the principles of reflection, image formation, and mirror magnification. Concepts include the properties of plane mirrors, the uses of concave mirrors in solar devices, and the behavior of light rays. These fundamentals are essential general science topics in major competitive examinations.

Plane mirror propertiesConcave mirror applicationsMirror magnification formulaLight reflection lawsImage formation

Light and Mirrors Questions

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

A perpendicular drawn at the point of incidence of a light ray on the surface of a mirror is called -

  1. incident ray

  2. reflected ray

  3. normal

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

Normal is perpendicular drawn to the surface at the point of incidence so that angle between incident ray and normal is angle of incidence.

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

When a beam of light, from an object, appears to meet at a point after reflection from a mirror, then the image formed is known as :

  1. real image

  2. virtual image

  3. incident image

  4. all of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

According to definition, when a beam of light appears to meet at a point, after reflection, from a mirror then the image formed is known as virtual image. It cannot be obtained on a screen.

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

One feature of image formed by plane mirrors is lateral inversion which means:

  1. the top part of the image appears downward and vice versa

  2. left and right sides of the image are interchanged

  3. image appears inverted both sideways and upside down

  4. all the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When a mirror forms an image, the left and right sides of the image are interchanged. This phenomenon is called lateral inversion as the image is laterally inverted.

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

Identify on which of the following, specular reflection would most likely to occur. 

  1. mirror

  2. wall

  3. sheet of paper

  4. ceiling.

  5. cat's fur
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The back of a mirror is usually covered with some sort of darkly colored, protective material to stop the silver coating from getting scratched, and also to reduce the risk of any light seeping through from behind. Silver reflects light better than almost anything else and that's because it gives off almost as many light as fall on it in the first place.

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

A person has a $18$cm wide face and his two eyes are separated by 8 cm.Find the minimum width of a mirror required for the person to view is face laterally is

  1. $9$cm
  2. $4$cm
  3. $5$cm
  4. $13$cm
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For minimum width -

i). Center of face and mirror must lie in perpendicular bisector of the line joining two eyes.
ii). Left eye must see right end point of face at the end of the mirror.
iii). Night eye must see left end point of face at then end of the mirror.
Now let, 
$F _1,F _2$ end points of face width $11E _1,E _2$ two eyes $11C-$ center of face.
$m _1.m _2-$ mirror end points
$m _1,m _2-$ projection of $m _1m _2$ on line joining two eyes.
Now, line joining two eyes should look like -
$F _1--E _1---m _1-C---m _2----E _2---F _2$
Due to symmetry,
$\Rightarrow F1E2=E1F2=13cm$
Also, $m _1,m _2$ must be midpoint of $F1E2$ and $E1F2$ respectively.
So, $E1m2=m1E2=\dfrac{13}{2}=6.5$
$E1m2=6.5$
$\Rightarrow E1C+Cm2=6.5$
     $4+Cm2=6,5$
     $Cm2=2.5$
similarly $m1C=2.5$
$\Rightarrow m1m2=m1C1C2=5cm=$ mirror width.
Hence, the answer is $5cm.$

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

A beam of light converges at point $P$. Now, a plane mirror is placed $20 \mathrm { cm }$ before the converging point $P$. The new converging point is

  1. $20 \mathrm { cm }$ infront of the mirror
  2. $20 \mathrm { cm }$ behind the mirror
  3. The separation between new converging point and previous converging point is $40 \mathrm { cm } $

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

A converging beam directed at a point 20 cm behind a mirror will reflect and converge at a point 20 cm in front of the mirror due to the law of reflection. The mirror effectively flips the virtual image of the convergence point.