Advertisements
Advertisements
प्रश्न
A simple microscope is used by watch repairers. Give reason.
Advertisements
उत्तर
When an object is placed within the focal length of a simple microscope, its magnified and erect image is obtained on the same side of the lens as that of the object. So, a watch repairer sees the minute parts of a watch very clearly with a simple microscope by adjusting the distance between the object and the lens. This helps in repairing the watch. Hence, a simple microscope is used by watch repairers.
APPEARS IN
संबंधित प्रश्न
A student focused the Sun rays using an optical device 'X' on a screen S as shown.
From this it may be concluded that the device 'X' is a (select the correct option)
(A) Convex lens of focal length 10 cm.
(B) Convex lens of radius of curvature 20 cm.
(C) Convex lens of focal length 20 cm.
(D) Concave mirror of focal length 20 cm.
Give one use each of a concave and a convex mirror.
Define the Focal length of a spherical mirror
What type of image is formed:
on a cinema screen?
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of a carbon paper for some time, a hole is burnt in the carbon paper.
What is the advantage of using a carbon paper rather than a white paper?
Write the formula for a lens connecting image distance (v), object distance (u) and the focal length (f). How does the lens formula differ from the mirror formula?
The diverging lens in part (a) is replaced by a converging lens also of focal length 100 mm. The object remains in the same position and an image is formed by the converging lens. Compare two properties of this image with those of the image formed by the diverging lens in part (a).
Explain the following terms :
Pole, Centre of curvature, Radius of curvature, Principal axis. Show them on separate diagrams for each of the concave and convex mirrors.
How is a spherical mirror used to converge a beam of light at a point? Name the type of mirror used.
Three mirrors are created from a single sphere. Which of the following - pole, centre of curvature, radius of curvature, principal axis - will be common to them and which will not be common?
Define linear magnification produced by a mirror?
Define focal length.
What is the difference between virtual images of an object formed by a concave mirror and a convex mirror?
For a spherical mirror, ______ is true.
A spherical mirror whose reflecting surface is curved outwards is called ______ mirror.
Explain why a ray of light passing through the center of curvature of a concave mirror, gets reflected along with the same pattern.
In the figure shown, the image of a real object is formed at the point I. AB is the principal axis of the mirror. The mirror must be:
A converging lens of focal length f is placed at a distance 0.3 m from an object to produce an image on a screen 0.9 m from the lens. With the object and the screen in the same positions, an image of the object could also be produced on the screen by placing a converging lens of focal length.
In normal adjustment, for a refracting telescope, the distance between objective and eye piece is 30 cm. The focal length of the objective, when the angular magnification of the telescope is 2, will be ______.
