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प्रश्न
State two uses of a concave mirror.
Give the uses of a concave mirror.
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उत्तर १
Two uses of concave mirror:
(i) It is used as a shaving mirror.
(ii) It is used as reflector in torch, head light of automobiles etc.
उत्तर २
The uses of a concave mirror are
(i) In torches and headlights: The source of light is placed at the focus to obtain a parallel beam of light.
(ii) In floodlights: The source of light is placed just beyond the center of curvature so as to get an intense beam of light.
(iii) Reflecting mirrors for projector lamps: The object is placed at the center of curvature to obtain an image of the same size.
- To collect heat radiations in solar devices: Heat radiations from the sum coming from infinity are brought to focus by a concave mirror in its focal plane.
- Shaving mirror, dentist’s mirror: It produces an erect virtual and highly magnified image of an object placed between its pole and focus.
vi. Solar furnaces: Large concave mirrors are used to concentrate sunlight to produce heat in a solar furnace.
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संबंधित प्रश्न
One half of a convex lens of focal length 10 cm is covered with a black paper. Can such a lens produce an image of a complete object placed at a distance of 30 cm from the lens? Draw a ray diagram to justify your answer. A 4 cm tall object is placed perpendicular to its principal axis of a convex lens of focal length 20 cm. The distance of the object from the lens is 15 cm. Find the nature, position and the size of the image.
A student focused the Sun rays using an optical device 'X' on a screen S as shown.
From this it may be concluded that the device 'X' is a (select the correct option)
(A) Convex lens of focal length 10 cm.
(B) Convex lens of radius of curvature 20 cm.
(C) Convex lens of focal length 20 cm.
(D) Concave mirror of focal length 20 cm.
Define the following term in the context of spherical mirrors:- Pole
Image formed by a convex ______ is always virtual and smaller in size.
An image which can be obtained on a screen is called a ______ image.
We can obtain an enlarged and erect image by a convex mirror.
A ray of light is incident on a plane mirror at an angle of 30°. What is the angle of reflection
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of a carbon paper for some time, a hole is burnt in the carbon paper.
What is the nature of spherical mirror?
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of a carbon paper for some time, a hole is burnt in the carbon paper.
At which point of the spherical mirror the carbon paper is placed?
A concave lens produces an image 20 cm from the lens of an object placed 30 cm from the lens. The focal length of the lens is:
(a) 50 cm
(b) 40 cm
(c) 60 cm
(d) 30 cm
A coin placed at the bottom of a vessel appears to be raised when water is poured in the vessel.
Explain the following terms :
Pole, Centre of curvature, Radius of curvature, Principal axis. Show them on separate diagrams for each of the concave and convex mirrors.
A student obtained on a screen the sharp image of a candle flame placed at the farther end of laboratory table using a concave mirror. For getting better value of focal length of the mirror, the teacher suggested to him to focus the sun. What should the student do?
(A) Should move the mirror away from the screen.
(B) Should move the mirror towards the screen.
(C) Should move the mirror and screen both towards the sun.
(D) Should move only the screen towards the sun.
Upto what maximum distance from the pole the image in a convex mirror can be obtained? what will be the location of object then ?
The image formed by a convex mirror is
The erect image formed by a concave mirror is of size double the size of object. How are u and v related?
Answer the following question.
Write the modification in the curvature of the eye lens which enables us to see the nearby objects clearly?
Define the following term in relation to concave mirror.
Center of curvature
What is the relation between focal length and radius of curvature of a concave mirror?
Define the term Focus of a concave mirror.
An object 10 cm high is placed at a distance of 20 cm in front of a spherical mirror of focal length 25 cm. By scale drawing find the nature, position, and magnification of the image in the following case:
Convex mirror
Complete the following diagrams shown in the below figure by drawing the reflected ray for each incident ray.
Name the type of mirror used in the following situation:
Side/rear-view mirror of a vehicle
Support your answer with reason.
In the figure shown, the image of a real object is formed at the point I. AB is the principal axis of the mirror. The mirror must be:
