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प्रश्न
If an object is placed at the focus of a convex lens, where is the image formed?
उत्तर
For an object placed at the focus of a convex lens, the image is formed at infinity.
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संबंधित प्रश्न
An object of height 2.5 cm is placed at a distance of 15 cm from the optical centre 'O' of a convex lens of focal length 10 cm. Draw a ray diagram to find the position and size of the image formed. Mark optical 'O', principal focus F and height of the image on the diagram.
Draw a labelled ray diagram to show how a ray of light passes through a parallel sided glass block:
if it hits the glass block at an angle other than 90° (that is, obliquely to the glass block).
Define principal axis, principal focus and focal length of a convex lens.
State whether convex lens has a real focus or a virtual focus.
An object 4 cm high is placed at a distance of 10 cm from a convex lens of focal length 20 cm. Find the position, nature and size of the image.
For finding the focal length of a convex lens by obtaining the image of a distant object, one should use as the object.
(1) a well lit distant tree
(2) window grill in the class room
(3) any distant tree
(4) a lighted candle kept at the other end of the table.
State the position of object, position of image, nature of image when: Convex lens is used as objective lens of astronomical telescope.
A candle is placed between f and 2f a convex lens. Draw a ray diagram showing the position of the image.
The above image shows a thin lens with a focal length of 5m.
- What is the kind of lens shown in the above figure?
- If a real inverted image is to be formed by this lens at a distance of 7m from the optical centre, then show with calculation where should the object be placed.
- Draw a neatly labelled diagram of the image formation mentioned in (ii).
Distinguish between:
Concave lens and Convex lens
