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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
Explain the following term related to spherical lenses:- optical centre
Define the following term in the context of spherical mirrors:- Principal axis
Explain the following term related to spherical lenses:- aperture
Explain the following term related to spherical lenses: focal length
What happens when a ray of light falls normally (or perpendiculary) on the surface of a plane mirror?
A ray of light is incident normally on a plane mirror. What will be the:
- angle of incidence?
- angle of reflection?
Name the two types of spherical mirrors. What type of mirror is represented by the:
front side of a shining steel spoon?
Define (a) centre of curvature (b) radius of curvature (c) pole (d) principal axis, and (e) aperture, of a spherical mirror with the help of a labelled diagram
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 name is given to the distance between spherical mirror and carbon paper?
Name the spherical mirror which can produce a real and diminished image of an object.
Define the following terms in the context of spherical mirrors :
(i) Pole
(ii) Centre of curvature
(iii) Radius of curvature
(iv) Principal axis
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.
State the types of mirrors used for (i) headlights and (ii) rear view mirror, in cars and motorcycles. Give to justify your answer in each case.
For what position of object, the image formed by a concave mirror is magnified and erect?
Discuss the position and nature of image formed by a convex mirror when an object is moved from infinity towards the pole of mirror.
(a) When a concave mirror is used as a shaving mirror, where is the person's face in relation to the focus of mirror?
(b) State three characteristics of the image seen in part (a).
How will you distinguish between a plane mirror, a concave mirror and a convex mirror, without touching them?
Draw a ray diagram to show the formation of image of an object kept in front of a convex mirror. State three characteristics of the image.
Answer the following question:
Distinguish between the convex mirror and the concave mirror.
Define the following term:
convex mirror
Assertion: Incident ray is directed towards the centre of curvature of spherical mirror. After reflection it retraces its path.
Reason: Angle of incidence (i) = Angle of reflection (r) = 0°
If the real image of a candle flame formed by a lens is three times the size of the flame and the distance between lens and image is 80 cm, at what distance should the candle be placed from the lens?
A spherical mirror whose reflecting surface is curved outwards is called ______ mirror.
Visit a nearby hospital. You can also visit the clinic of an ENT specialist, or a dentist. Request the doctor to show you the mirrors used for examining ear, nose, throat and teeth. Can you recognise the kind of mirror used in these instruments?
