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प्रश्न
_______ is a combination of two convex lenses with small focal length.
पर्याय
simple microscope
compound microscope
telescope
none of these
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उत्तर
Compound microscope is a combination of two convex lenses with small focal length.
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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.
To determine the approximate focal length of the given convex lens by focussing a distant object (say, a sign board), you try to focus the image of the object on a screen. The image you obtain on the screen is always
(a) erect and laterally inverted
(b) erect and diminished
(c) inverted and diminished
(d) virtual, inverted and diminished
Draw a ray diagram to show the formation of the image of an object be placed so that a real and inverted image of the same size as the object is obtained using a convex lens
For what position of an object a real, diminished image is formed by a convex lens?
What type of lens would you use as a magnifying glass? How close must the object be to the lens?
Name one simple optical instrument in which the above arrangement of convex lens is used.
Which of the above two cases illustrates the working of a magnifying glass?
A student did an experiment with a convex lens. He put an object at different distances 25 cm, 30 cm, 40 cm, 60 cm and 120 cm from the lens. In each case he measured the distance of the image from the lens. His results were 100 cm, 24 cm, 60 cm, 30 cm and 40 cm, respectively. Unfortunately his results are written in wrong order.
- Rewrite the image distances in the correct order.
- What would be the image distance if the object distance was 90 cm?
- Which of the object distances gives the biggest image?
- What is the focal length of this lens?
Which causes more bending (or more refraction) of light rays passing through it : a convex lens of long focal length or a convex lens of short focal length?
Complete the following sentence.
A long-sighted person cannot see ........... objects clearly. Long-sightedness can be corrected by using .............. lenses.
The focal length of a thin convex lens is ______ than that of a thick convex lens.
A lens forms an erect, magnified, and virtual image of an object.
- Name the type of lens.
- Draw a ray diagram to show the formation of the image.
- Where is the object placed in relation to the lens?
- Name the device which uses this principle.
If you are to determine to focal length of a convex lens, you should have
(A) a convex lens and a screen
(B) a convex lens and a lens holder
(C) a lens holder, a screen holder and a scale
(D) a convex lens, a screen, holder for them and a scale
Yesh find out F1 and F2 of symmetric convex lens experimentally then which conclusion is true.
State the position of object, position of image, nature of image when: Convex lens is used as in searchlight.
Which lens can produce a real and inverted image of an object?
Object at 2F1 of a convex lens : Image at 2F2 : : Object at F1 : _______
Simple microscope : Number of convex lens one : : compound microscope : _______
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.
