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प्रश्न
Draw a ray diagram for concave mirror when the object is between centre of curvature and focus.
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उत्तर
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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संबंधित प्रश्न
Consider the following diagram in which M is a mirror and P is an object and Q is its magnified image formed by the mirror.
State the type of the mirror M and one characteristic property of the image Q.
The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object?
Three students A, B and C focussed a distant building on a screen with the help of a concave mirror. To determine focal length of the concave mirror they measured the distances as given below:
Student A : From mirror to the screen
Student B : From building to the screen
Student C : From building to the mirror
Who measured the focal length correctly ;
(a) Only A
(b) Only B
(c) A and B
(d) B and C
Find the focal length of a concave mirror whose radius of curvature is 32 cm.
For what position of an object, a real and diminished image is formed by a concave mirror?
Make labelled ray diagrams to illustrate the formation of:
a real image by a converging mirror.
A concave mirror has a focal length of 25 cm. At which of the following distance should a person hold his face from this concave mirror so that it may act as a shaving mirror?
(a) 45 cm
(b) 20 cm
(c) 25 cm
(d) 30 cm
Give reason for your choice.
According to the "New Cartesian Singh Convention" for mirrors, what sign has been given to the focal length of:
a concave mirror?
What is the position of the image when an object is placed at a distance of 20 cm from a concave mirror of focal length 20 cm?
At what distance from a concave mirror focal length 10 cm should an object 2 cm long be placed in order to get an erect image 6 cm tall?
When an object is placed at a distance of 15 cm from a concave mirror, its image is formed at 10 cm in front of the mirror. Calculate the focal length of the mirror.
A bright object 50 mm high stands on the axis of a concave mirror of focal length 100 mm and at a distance of 300 mm from the concave mirror. How big will the image be?
If a concave mirror has a focal length of 10 cm, find the two positions where an object can be placed to give, in each case, an image twice the height of the object.
If the image formed is always virtual, the mirror can be:
(a) concave or convex
(b) concave or plane
(c) convex or plane
(d) only convex
Why are concave mirrors used in solar devices?
An object at a distance of 30 cm from a
concave mirror gets its image at the same point. The focal length of the mirror is ______.
An erect and enlarged image can be formed by
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.
