Physics

Light and Mirrors

458 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 evs reflection of light by plane surfaces characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

An object is placed at a distance of $0.25m$ in front of a plane mirror. The distance between the object and the image is:

  1. $0.5m$
  2. $1m$
  3. $0.25m$
  4. $0.75m$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For reflection from a plane mirror, distance between object and mirror $=$ distance between mirror and the image$=0.25m$

So, distance between object and image$=$ (distance between object and mirror) $+$ (distance between mirror and image) $=(0.25+0.25)m=0.5m$

Multiple choice evs reflection of light by plane surfaces characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

If a mirror forms a virtual image of a real object then

  1. it must be a convex mirror.

  2. it must be concave mirror.

  3. it must be a plane mirror.

  4. it may be any of the mirrors mentioned above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A mirror that forms a virtual image of a real object is :
(a) Concave mirror: When object is placed only between pole and focus of the mirror.
(b) Convex mirror: For all positions of objects, image is virtual.
(c) Plane mirror: Image formed is virtual.

Multiple choice evs reflection of light by plane surfaces characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

Which type of an image is formed by a plane mirror?

  1. Real & inverted

  2. Real & erect

  3. Virtual & erect

  4. Virtual & inverted
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The image that is formed by a plane mirror will be virtual, upright, same size and inverted

The object distance and the image distance will be equal.

Thus, the image formed by a plane mirror is virtual and inverted.

Multiple choice evs reflection of light by plane surfaces characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

Image formed by a plane mirror is
a) of same size as that of object
b) at the same distance behind the mirror as the object in front
c) erect, virtual
Mark the correct statements:

  1. a and b

  2. b and c

  3. a and c

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

Image formed by a plane mirror is of same size as that of object and is formed at the same distance behind the mirror as object is in front of the mirror.

And the image formed is virtual, erect and laterally inverted.

Answer-(D)

Multiple choice physics solar equipment production of electricity from solar energy solar power alternate sources of energy solar power plant solar energy and its applications renewable and non-renewable resources renewable and non-renewable sources of energy generation of electricity

What is fixed at the top of solar cooker?

  1. Plane mirror or concave mirror

  2. Convex mirror

  3. bifocal mirror

  4. Cylindrical mirror
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Concave or plain mirror is used in the solar cooker in order to concentrate the sunlight at one spot.

Multiple choice maths position and movement reflection w.r.t a line transformation transformation and symmetry in geometrical shapes

The distance of the image of a point (or an object) from the line of symmetry (mirror) is  ----- as that of the point (object )from the line (mirror).

  1. same

  2. double

  3. triple

  4. none
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
To make the above statement true, the word to be placed in the blank is : “same”
So, the true statement becomes :
The distance of the image of a point (or an object) from the line of symmetry (mirror) is same as that of the point (object) from the line (mirror).
Hence, option A is the correct answer.
Multiple choice maths position and movement reflection w.r.t a line transformation transformation and symmetry in geometrical shapes

The image of the pair of lines represented by$\displaystyle :ax^{2}+2hxy+by^{2}= 0 $ by the line $ y= 0 $ mirror is:

  1. $\displaystyle \:ax^{2}-2hxy-by^{2}= 0$
  2. $\displaystyle \:bx^{2}-2hxy+ay^{2}= 0$
  3. $\displaystyle \:bx^{2}+2hxy+ay^{2}= 0$
  4. $\displaystyle \:ax^{2}-2hxy+by^{2}= 0$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In ${ ax }^{ 2 }+2hxy+{ by }^{ 2 }=0 $ replacing $y$ by $-y$
we get, ${ ax }^{ 2 }+2hx\left( -y \right) +{ by }^{ 2 }=0 $
$\Rightarrow { ax }^{ 2 }-2hxy+{ by }^{ 2 }=0 $

Multiple choice maths position and movement reflection w.r.t a line transformation transformation and symmetry in geometrical shapes

If the image of the point $ \displaystyle \left ( 4,-6 \right ) $ by a line is the point $(2,2)$, then the equation of the mirror is

  1. $ \displaystyle 4x+3y-5= 0 $
  2. $ \displaystyle x-4y= 11 $
  3. $ \displaystyle x+4y-5= 0 $
  4. $ \displaystyle -x+y+11= 0 $
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

From given points, required line and line joining points are perpendicular to each other,


$\displaystyle \therefore$ slope of required line is $\displaystyle m=-\frac { 2-4 }{ 2-(-6) } =\frac { 1 }{ 4 } $

The midpoint of the given points will be on our line.

$\Rightarrow$$X=\left ( \dfrac{x _1+x _2}{2}\right ) and \ Y=\left ( \dfrac{y _1+y _2}{2}\right )$

$\Rightarrow$$X=\left ( \dfrac{4+2}{2}\right ) =3 \ and \ Y=\left ( \dfrac{-6+2}{2}\right )=-2$

$\displaystyle \therefore$ point is $\displaystyle (3,-2)\equiv(x _1,y _1)$.

$\therefore$ Equation of line is given by, 

$\Rightarrow$$y-y _1=m(x-x _1)$

Then equation of required line is $\displaystyle \frac { y+2 }{ x-3 } =\frac { 1 }{ 4 } \Longrightarrow x-4y=11$

Multiple choice physics light, shadows and reflections characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

A plane mirror is made up of:

  1. a few metre thick glass plate

  2. a few mm thick glass plate

  3. a few cm thick glass plate

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

A plane mirror is made from a few mm thick glass plate. The front part is highly polished and the back part is silvered.

Multiple choice evs light, shadows and reflections characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

When the distance between the object and the plane mirror increases :

  1. The image remains same

  2. The size of the image will become less than the size of the object.

  3. The distance between the image and the plane mirror increases

  4. The distance between the image and the plane mirror decreases
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When the distance between the object and the plane mirror increases because the distance between the image and the plane mirror increases.

Multiple choice evs light, shadows and reflections characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

Which of the following are the properties of plane mirror images?

  1. The image is the same size as the object

  2. The image is virtual

  3. The image is inverted

  4. Image distance is equal to object distance
Reveal answer Fill a bubble to check yourself
A,B,D Correct answer
Explanation

In case of a plane mirror, image is virtual, erect, same size as the object and image distance is equal to object distance.

Multiple choice evs light, shadows and reflections characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

A point object is placed midway between two plane mirrors a distance apart. The plane mirrors form an infinite number of images due to multiple reflections. The distance between nth order images formed in the two mirrors is

  1. $n a$
  2. $2 n a$
  3. $0.5 n a$
  4. ${ n }^{ 2 }a$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When an object is placed midway between two parallel mirrors separated by distance 'a', the images are formed at distances 0.5a, 1.5a, 2.5a, etc., from each mirror. The distance between the nth order images is 0.5na.