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Question
Draw a ray diagram for concave mirror when the object is between centre of curvature and focus.
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Solution
When the object is between the centre of curvature and the focus of a concave mirror
Here, Object AB is kept between C and F
First, we draw a ray parallel to principal axis
So, it passes through focus after reflection
We draw another ray which passes through Center of Curvature
So, the ray will go back along the same path after reflection
Where both reflected rays meet is point A'
And the image formed is A'B'
This image is formed between beyong Center(C)
We can say that
Image is in Front of the mirror (Real image)
Image is Inverted
Image is larger than the object (Magnified)
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| 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.
