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प्रश्न
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.
Why is a hole burnt in the carbon paper?
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उत्तर
A concave mirror converges light rays, and in this case it will converge the incoming parallel rays of the sun at its focus. Since the carbon paper was kept at the focus of the concave mirror, the hole was burnt into it.
संबंधित प्रश्न
Explain the following term related to spherical lenses:- principal focus
Name the two types of spherical mirrors. What type of mirror is represented by the:
- back side of a shining steel spoon?
- front side of a shining steel spoon?
Write the mirror formula. Give the meaning of each symbol which occurs in it.
The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror:
Which type of spherical mirror will it provide?
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 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.
If a spherical mirror breaks, what type of mirrors are the individual pieces?
Three mirrors are created from a single sphere. Which of the following - pole, centre of curvature, radius of curvature, principal axis - will be common to them and which will not be common?
Figure shows a concave mirror with its pole at P, focus F and centre of curvature C. Draw ray diagram to show the formation of image of an object OA.
The diagram below in Figure, shows a convex mirror. C is its centre of curvature and F is its focus. (i) Draw two rays from A and hence locate the position of image of object OA. Label the image IB. (ii) State three characteristics of the image.
Why does a driver use a convex mirror instead of a plane mirror as a rear view mirror?
Illustrate your answer with the help of a ray diagram.
A point light source is kept in front of a convex mirror at a distance of 40 cm. The focal length of the mirror is 40 cm. Find the position of image.
An object forms a virtual image which is 1/8th of the size of the object. If the object is placed at a distance of 40 cm from the convex mirror, calculate:
- the position of the image
- the focal length of the convex mirror.
Select the correct option:
A concave mirror is made by cutting a portion of a hollow glass sphere of radius 30 cm. The focal length of the concave mirror is:
Define the following term:
convex mirror
Define the term principal focus in case of convex mirror. Draw a convex mirror and show its principal focus and focal length clearly.
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?
