# CBSE Class 10th Science 10 – Reflection and Refraction MCQs

#### For a concave mirror the focal length is ____ and the radius of curvature is ____.

Correct! Wrong!

For a concave mirror the both focal length and radius of the curvature are taken negative.

#### When an object and its image have different orientation, its magnification is negative.

Correct! Wrong!

Negative magnification means the object and image have different orientation. If the object is erect, then the image is inverted or vice versa.

#### Light travels faster in ____.

Correct! Wrong!

Light travels faster in vacuum. It has a velocity, equal to 3 ×108 m/s.

#### The distance of the image of an object is measured from the ____ of the spherical mirror.

Correct! Wrong!

The distance of image of an object is measured from the pole of the spherical mirror. It is denoted by ' v '.

#### Magnification is equal to the ratio of the size of the image to the size of the object.

Correct! Wrong!

The ratio of the size of the image to the size of object is known as magnification and it is calculated as, m = himage/hobject Here, himage = height of image; hobject = height of object.

#### Linear magnification of a mirror has no units.

Correct! Wrong!

Linear magnification of a mirror is defined as the ratio of the height of the image (hi) to the height of the object (ho). It is a pure ratio and has no units

#### An object ‘O’ is placed at a distance‘d’ from a plane mirror. If the object is moved a distance 'x' away from the mirror, the image moves a distance ____ away from the mirror.

Correct! Wrong!

An object ‘O’ is placed at a distance ‘d’ from a plane mirror. If the object is moved a distance 'x' away from the mirror, the image moves a distance 'x' away from the mirror.

#### A convex mirror always produces ____ and ____ images.

Correct! Wrong!

A convex mirror always produces virtual and diminished image irrespective of the position of the object in front of the mirror.

#### The side way reversal of the image by a plane mirror is called ____.

Correct! Wrong!

The side way reversal of the image by a plane mirror is called lateral inversion.

#### The reflection which takes places from the ground, walls, trees, suspended particles in the air and a variety of other objects which are not very smooth, is called ____.

Correct! Wrong!

The reflection which takes places from the ground, walls, trees, suspended particles in the air and a variety of other objects which are not very smooth, is called irregular reflection.

#### A real image is always erect.

Correct! Wrong!

A real image is always inverted with respect to the object and it can be obtained on a screen.

#### The radius of curvature of a concave mirror is −30 cm. Its focal length is ____ cm.

Correct! Wrong!

Given, Radius of curvature, R = −30 cm R = 2f ⇒ f = −30 cm/2 ∴ f = −15 cm Hence, the focal length of concave mirror is −15 cm.

#### Which of the following medium is optically more denser?

Correct! Wrong!

Diamond is optically more denser compared to others.

#### A ____ is a diverging lens.

Correct! Wrong!

A concave lens is the diverging lens.

#### Which of the following is not an example of refraction?

Correct! Wrong!

Image in a mirror is an example of the reflection phenomenon.

#### Distances measured above the principal axis are taken as positive.

Correct! Wrong!

According to the new cartesian sign convention, distances measured above the principal axis are taken as positive.

#### A plane mirror can also be called as spherical mirror.

Correct! Wrong!

A plane mirror can also be called as spherical mirror of infinite focal length.

#### When a ray is travelling from a rarer medium to the denser medium, the ray will move away from the normal.

Correct! Wrong!

When a ray is travelling from a rarer medium to the denser medium, the ray will move towards the normal.

#### The lens which is thicker at the centre and thinner at the periphery is called a ____ lens.

Correct! Wrong!

A convex lens is thicker at the centre and thinner at the periphery.

#### Which mirror has a large field of view?

Correct! Wrong!

A convex mirror has a large field of view, which can be used as a rear view mirror, as a reflector in street lights etc.

#### According to the laws of reflection, ∠i ≠ ∠r (where all symbols have their standard meaning).

Correct! Wrong!

According to laws of reflection, the angle of incidence is equal to the angle of reflection.

#### Which of the following characteristics represent the image formed by a plane mirror?

Correct! Wrong!

A plane mirror forms a virtual image of an object such that, the height of the image is equal to the height of object and the distance of the image from the mirror is equal to the distance of the object from the mirror.

#### A ray of light is incident on the plane mirror normally. The angle of incidence and the angle of reflection are ____ respectively.

Correct! Wrong!

When a ray is incident on the plane mirror normally, the ray gets reflected back into the medium along the incident ray. Hence, the angle of incidence and the angle of reflection are 0° and 0° respectively.

#### The amount of light reflected depends upon ____.

Correct! Wrong!

The amount of light reflected depends upon, nature and smoothness of the surface.

#### Any incident ray travelling parallel to the principal axis of a diverging lens will refract through the lens and travel through the focal point on the other side of the lens.

Correct! Wrong!

Any incident ray travelling parallel to the principal axis of a diverging lens after refraction will move away from the principal axis. It does not travel through the focal point on the other side of the lens.

#### Which one of the following mirrors is used by ENT specialists and dentists?

Correct! Wrong!

Concave mirrors are used by dentists and ENT specialists to focus light on the teeth, nose, eye, and throat to examine those organs.

#### The phenomenon, due to which a beam of light, travelling through a certain medium, on striking some smooth polished surface, bounces off from it in some other direction, is called ____ of light.

Correct! Wrong!

The phenomenon, due to which a beam of light, travelling through a certain medium, on striking some smooth polished surface, bounces off from it in some other direction, is called reflection of light.

#### Which of the following represent the units of linear magnification?

Correct! Wrong!

Linear magnification is the ratio of the same physical quantities, hence, it has no units.

#### A coin present at the bottom of a beaker filled with water appears to be raised. This is due to ____ of light.

Correct! Wrong!

Due to refraction, the coin present at the bottom of a beaker filled with water appears to be raised.

#### ____ can be thought of as a series of tiny refracting prisms, each of which refracts light to produce their own image.

Correct! Wrong!

Lenses can be thought of as a series of tiny refracting prisms, each of which refracts light to produce their own image. When these prisms act together, they produce a bright image focused at a point.

CBSE Class 10th Science 10 - Reflection and Refraction MCQs
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