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प्रश्न
ill in the following blank with suitable word:
For a convex mirror, parallel rays of light appear to diverge from a point called the ......... .
उत्तर
For a convex mirror, parallel rays of light appear to diverge from a point called the focus.
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संबंधित प्रश्न
With the help of an appropriate ray diagram, state the sign conventions for reflection by a spherical mirror.
Name the type of mirror used by dentists. How does it help?
According to the "New Cartesian Singh Convention" for mirrors, what sign has been given to the focal length of:
a convex mirror?
Describe the nature of image formed when the object is placed at a distance of 20 cm from a concave mirror of focal length 10 cm
Which of the following can make a parallel beam of light from a bulb falls on it?
(a) concave mirror as well as concave lens
(b) convex mirror as well as concave lens
(c) concave mirror as well as convex lens
(d) concave mirror as well as convex lens
Complete the following diagrams in figure by drawing the reflected rays for the incident rays 1 and 2 if F is the focus and C is the centre of curvature.
A concave mirror of focal length 20 cm forms an image having twice the size of object. For the virtual position of object, the position of object will be at ______.
______ mirrors make things look larger when objects are placed close to them.
A student wants to obtain an erect image of an object using a concave mirror of 10 cm focal length. What will be the distance of the object from mirror?
A student took three concave mirrors of different focal lengths and performed the experiment to see the image formation by placing an object at different distance with these mirrors as shown in the following table.
| Case No. | Object-distance | Focal length |
| I | 45 cm | 20 cm |
| II | 30 cm | 15 cm |
| III | 20 cm | 30 cm |
Now answer the following questions:
(a) List two properties of the image formed in Case I.
(b) In which one of the cases given in the table, the mirror will form real image of same size and why?
(c) Name the type of mirror used by dentists. Given reason why do they use such type of mirrors.
OR
(c) Look at the table and identify the situation (object distance and focal length) which resembles the situation in which concave mirrors are used as shaving mirrors? Draw a ray diagram to show the image formation in this case.
