Practice Challenge -Subjective
Subject: Physics
Topic : Light :Reflection and
Refraction Class: Standard X
1. Find the focal length of a convex mirror whose radius of curvature is 32 cm.
Radius of curvature, R = 32 cm
Radius of curvature = 2× focal length (f)
(1 mark)
R 32 cm
f = = = 16 cm
2 2
Hence, the focal length of the given convex mirror is 16 cm.
2. We wish to obtain an erect image of an object, using a concave mirror of
focal length 15 cm. What should be the range of distance of the object from
the mirror? What is the nature of the image? Is the image larger or smaller
than the object? Draw a ray diagram to show the image formation in this
case.
Range of object distance should be 0 cm to 15 cm because a concave
mirror gives an erect image when an object is placed between its pole (P)
and the principal focus (F).
Hence, to obtain an erect image of an object from a concave mirror of focal
length 15 cm, the object must be placed anywhere between the pole and
the focus.
(2 marks)
The image formed will be virtual, erect and magnified in nature, as shown in
the given figure.
(1 mark)
(2 marks)
Copyright © Think and Learn Pvt. Ltd. Light :Reflection and Refraction
, Practice Challenge -Subjective
3. Name the type of mirror used in the following situations.
(a) Headlights of a car.
(b) Side/rear-view mirror of a vehicle.
(c) Solar furnace.
Support your answer with reason.
(a) In headlights of a car, type of mirror is concave as the light of the lamp,
undergoes divergence from reflector surface and cover a large area in the
front. (1 mark)
(b) Side/rear-view mirror of a vehicle Convex mirror is used. This is because
a convex mirror has a larger field of view compared to other mirrors.
(1 mark)
(c) Concave mirror is used to design solar furnaces .
When a solar furnace is placed at the focus of a large concave mirror called
reflector, it focuses parallel beam of light coming from the sun on the
furnace and the high temperature is achieved. (1 mark)
Copyright © Think and Learn Pvt. Ltd. Light :Reflection and Refraction
Subject: Physics
Topic : Light :Reflection and
Refraction Class: Standard X
1. Find the focal length of a convex mirror whose radius of curvature is 32 cm.
Radius of curvature, R = 32 cm
Radius of curvature = 2× focal length (f)
(1 mark)
R 32 cm
f = = = 16 cm
2 2
Hence, the focal length of the given convex mirror is 16 cm.
2. We wish to obtain an erect image of an object, using a concave mirror of
focal length 15 cm. What should be the range of distance of the object from
the mirror? What is the nature of the image? Is the image larger or smaller
than the object? Draw a ray diagram to show the image formation in this
case.
Range of object distance should be 0 cm to 15 cm because a concave
mirror gives an erect image when an object is placed between its pole (P)
and the principal focus (F).
Hence, to obtain an erect image of an object from a concave mirror of focal
length 15 cm, the object must be placed anywhere between the pole and
the focus.
(2 marks)
The image formed will be virtual, erect and magnified in nature, as shown in
the given figure.
(1 mark)
(2 marks)
Copyright © Think and Learn Pvt. Ltd. Light :Reflection and Refraction
, Practice Challenge -Subjective
3. Name the type of mirror used in the following situations.
(a) Headlights of a car.
(b) Side/rear-view mirror of a vehicle.
(c) Solar furnace.
Support your answer with reason.
(a) In headlights of a car, type of mirror is concave as the light of the lamp,
undergoes divergence from reflector surface and cover a large area in the
front. (1 mark)
(b) Side/rear-view mirror of a vehicle Convex mirror is used. This is because
a convex mirror has a larger field of view compared to other mirrors.
(1 mark)
(c) Concave mirror is used to design solar furnaces .
When a solar furnace is placed at the focus of a large concave mirror called
reflector, it focuses parallel beam of light coming from the sun on the
furnace and the high temperature is achieved. (1 mark)
Copyright © Think and Learn Pvt. Ltd. Light :Reflection and Refraction
