Light(7th Grade > Physics ) Questions and answers for exam Preparation

7th Grade > Physics

LIGHT MCQs

Total Questions : 117 | Page 7 of 12 pages

Question 61.

Convex mirror is also known as a divergent mirror.

True
False
Convex
Plano convex

Discuss Question

Answer: Option A. -> True
:
A

A convex mirror is a divergent mirror and a concave mirror is a convergent mirror.

Convex mirrors are called diverging mirrors because they diverge rays of light that hit them and form a virtual image.

Concave mirrors are called converging mirrors because they bring incoming parallel rays together and cause these rays to converge.

Question 62.

Concave mirror always forms a virtual image.

True
False
Convex
Plano convex

Discuss Question

Answer: Option B. -> False
:
B

Convex mirror always forms a virtual image. A concave mirror can form a real or a virtual image depending on the distance of the object and the mirror.

Question 63.

Name the lens which is thinner at the center and thicker at the edges.

Prism
Concave
Convex
Plano convex

Discuss Question

Answer: Option B. -> Concave
:
B
A concave lens is thicker at the edges than in the middle. It diverges an incident parallel beam of light.
A convex lens is thicker in the middle than at the edges. It converges an incident parallel beam of light.

Name The Lens Which Is Thinner At The Center And Thicker At ...

Question 64.

We can obtain an enlarged and erect image with a convex mirror.

True
False
Convex
Plano convex

Discuss Question

Answer: Option B. -> False
:
B

We cannot obtain an enlarged and erect image using a convex mirror. The image obtained with a convex mirror is virtual, upright and diminished in size.

Question 65.

Image formed by a ____________ mirror is always of the same size as the object.

plane
concave
convex
spherical

Discuss Question

Answer: Option A. -> plane
:
A

Image formed by a plane mirror is erect and always of the same size as the object. The image formed by a convex mirror is upright but reduced in size whereas in a concave mirror the size of image is not fixed.

Question 66.

If the reflecting surface is curved outwards it is a convex mirror.

True
False
Convex
Plano convex

Discuss Question

Answer: Option A. -> True
:
A
If the reflecting surface is curved outwards it is a convex mirror. A convex mirror always forms a virtual, erect and diminished image. A convex mirror is a divergent mirror i.e it has wide field of view. Hence, the convex mirror is used as a side-view mirror in vehicles.

Question 67.

A concave lens always forms a virtual image.

True
False
Convex
Plano convex

Discuss Question

Answer: Option A. -> True
:
A

A concave lens always forms a virtual image no matter where the object is. A concave lens is a diverging lens. It causes light to spread out, resulting in a smaller image for the viewer.

Question 68.

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

Discuss Question

Answer: Option A. -> True
:

Answer: 1 Mark
The focal length of a plane mirror is infinite as the radius of its curvature is infinite.

Question 69.

Why is the mirror image of AMBULANCE written on the ambulance? [2 MARKS]

Discuss Question

Answer: Option A. -> True
:
Concept: 1 Mark
Reason: 1 Mark
Whenever an object is viewed through a mirror, its mirror image is formed.
The mirror image of AMBULANCE is written on the vehicle because any person who is driving ahead of the ambulance will instantly identify the vehicle as an ambulance because the image formed in the rear view will read as "AMBULANCE".

Why Is The Mirror Image Of AMBULANCE Written On The Ambulanc...

Question 70.

State the laws of reflection. [2 MARKS]

Discuss Question

Answer: Option A. -> True
:

Statements: 1 Mark each
The two laws of reflection are:
1. The angle of incidence is equal to the angle of reflection.
2. The incident ray, reflected ray and the normal lie on the same plane.