Introduction of Mirror

Q. The image formed by a plane mirror is always _________.

1. real and erect
2. real and inverted
3. virtual and erect
4. virtual and inverted

Q.

Define the term Conjugate Foci.

Q.

Why optician's use plane mirror?

1. All of the above

2. to use lateral inverted images.

3. to increase intensity of light entering the eye.

4. to increase effective length between object and image.

Q.

A periscope works on principle of

1. refraction of light

2. scattering

3. dispersion

4. reflection of light

Q.

Which of the following correctly represents the graphical relation between the angle of incidence (i) and angle of reflection (r)?

1. 

2. 

3. 

4. 

Q.

When two plane mirrors are placed parallel and facing each other, and an object is kept in between them, we get infinite images. But actually, only a few images are visible because the intensity of the image is:

1. increased after each reflection

2. decreased after each reflection

3. always constant

4. none of these

Q.

Periscope is based on the reflection of light.

1. True
2. False

Q.

A perfectly reflecting mirror has an area of $1c{m}^2$. Light energy is allowed to fall on it for $1h$ at the rate of $10Wc{m}^{-2}$. The force that acts on the mirror is

1. $3.35\times {10}^{-8}N$

2. $6.7\times {10}^{-8}N$

3. $1.34\times {10}^{-7}N$

4. $2.4\times {10}^{-4}N$

Q. Laser light of wavelength 660nm is used to weld a retina detachment. If the pulse has width 60 ms and power 0.5 KW the approximate number of photons in the pulse are?

Q.

What is the focal length of a plane mirror? [1 MARK]

Q.

State the laws of reflection. [2 MARKS]

Q.

What is the focal length of plane mirror? [1 MARKS]

Q. List the qualities that a good mirror must have.

Q.

Give reasons for the following -

Aluminium is used for making concave mirrors for astronomical telescopes.

Q.

The geometrical center of a spherical mirror is called its pole.

1. True
2. False

Q.

The application(s) of plane mirror is/are

1. used as looking glass

2. used in optician's room

3. used in barber's shop

4. used in periscope and kaliedoscope

Q.

What are three characteristics of an image formed by plane mirrors? [3 MARKS]

Q.

Which of the following is/are true?

1. A plane mirror has a smooth surface.

2. A plane mirror can alter the path of light rays falling on its surface.

3. A plane mirror has a rough surface, so as to produce a clear image.

4. A plane mirror is transparent.

Q. Rahul performs an experiment of image formation with an optical instrument (various mirrors and lenses) and finds that the image formed is a diminished virtual image. What kind of optical instrument did Rahul use?

1. Convex mirror and concave mirror
2. Concave mirror and convex lens
3. Convex mirror and convex lens
4. Convex mirror and concave lens

Q. Which of the following cannot be formed by a plane mirror?

1. A virtual image
2. An erect image
3. A diminished image
4. An image at the same distance as the object

Q.

In barber's shop, two plane mirros are placed

1. perpendicular to each other

2. parallel to each other

3. at an angle of 45 degree to each other

4. at an angle of 60 degree to each other

Q.

Five spherical mirrors are made from the same sphere. The uncommon thing among the mirrors is……….

1. radius of curvature

2. focal length

3. pole

4. None of these

Q. What is conjugate foci? Explain.

Q. Rahul performs an experiment of image formation with an optical instrument (various mirrors and lenses) and finds that the image formed is a diminished virtual image. What kind of optical instrument did Rahul use?

1. Convex mirror and concave mirror
2. Concave mirror and convex lens
3. Convex mirror and convex lens
4. Convex mirror and concave lens

Q. One surface of mirror is made opaque by______ it followed by a thin coating of paint of lead oxide.

Q. An object A is placed at a distance 'd' in front of a plane mirror. If one stand s directly behind the object at distance 's' from the mirror, then the distance of the image of A from the individual is

1. 2s
2. 2d
3. s + d
4. s + 2d

Q. A ray of light strikes a mirror at an angle of ${60}^o$ to the normal. The mirror is then rotated ${18}^o$ anticlockwise, What is the angle that the initial reflected ray and final reflected ray will have?

1. ${18}^o$
2. ${20}^o$
3. ${36}^o$
4. ${54}^o$

Q. A plane mirror is made up of:

1. a few metre thick glass plate
2. a few mm thick glass plate
3. none of these
4. a few cm thick glass plate

Q. A boy is standing in front of a plane mirror at a distance of 3 m from it, if the boy moves 1 m backward, the distance between the image and the boy is

1. 2 m
2. 4 m
3. 8 m
4. none of these

Q. A perfectly reflecting mirror has an area of $1c{m}^2$. Light energy is allowed to fall on it for $1h$ at the rate of $10W/c{m}^2$. The force that acts on the mirror is:

1. $3.35\times {10}^{-8}N$
2. $6.7\times {10}^{-8}N$
3. $1.34\times {10}^{-7}N$
4. $2.4\times {10}^{-4}N$