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प्रश्न
A spherical mirror produces an image of magnification -1 on a screen placed at a distance of 50 cm from the mirror.
(a) Write the type of mirror.
(b) Find the distance of the image from the object.
(c) What is the focal length of the mirror?
(d) Draw the ray diagram to show the image formation in this case.
उत्तर
(a) As magnification is negative, the image formed is real.
Hence, it is a concave mirror.
(b) `m=-v/u=-1`
`therefore u=v=-50" cm"`
`"Distance of the image from the object ="|u|+|v|=100" cm"`
(c) By using mirror formula:-
`1/f=1/v+1/u=1/((-50))+1/((-50))=-1/25`
`therefore f=-25" cm"`
(d)
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संबंधित प्रश्न
An object is held 20 cm away from a converging lens of focal length 10 cm. Find the position of the image formed.
Linear magnification produced by a concave mirror may be:
(a) less than 1 or equal to 1
(b) more than 1 or equal than 1
(c) less than 1, more than 1 or equal to 1
(d) less than 1 or more than 1
In order to obtain a magnification of −2 (minus 2) with a concave mirror, the object should be placed:
(a) between pole and focus
(b) between focus and centre of curvature
(c) at the centre of curvature
(d) beyond the centre of curvature
In order to obtain a magnification of, −0.6 (minus 0.6) with a concave mirror, the object must be placed:
(a) at the focus
(b) between pole and focus
(c) between focus and centre of curvature
(d) beyond the centre of curvature
The lens A produces a magnification of, − 0.6 whereas lens B produces a magnification of + 0.6.
What is the nature of lens A?
A student wants to project the image of a candle flame on a screen 80 cm in front of a mirror by keeping the candle flame at a distance of 20 cm from its pole.
- Which type of mirror should the student use?
- Find the magnification of the image produced.
- Find the distance between the object and its image.
- Draw a ray diagram to show the image formation in this case and mark the distance between the object and its image.
The image of a candle flame placed at a distance 30 cm from a spherical lens is formed on a screen placed at a distance of 60 cm from the lens. Identify the type of lens and calculate its focal length. If the height of the flame is 2.4 cm, find the height of its image.
What do you understand by the term magnification?
An object is placed vertically at a distance of 20 cm from a convex lens. If the height of the object is 5 cm and the focal length of the lens is 10 cm, what will be the position, size and nature of the image? How much bigger as compared to the object?
What information about the nature of image is erect or inverted, do you get from the sign of magnification + or -?
