Advertisements
Advertisements
प्रश्न
Magnifying power of a simple microscope is inversely proportional to the focal length of the lens. What then stops us from using a convex lens of smaller and smaller focal length and achieving greater and greater magnifying power?
उत्तर
Firstly, the process of making lenses with very short focal lengths (thick lenses) is not easy; secondly, as the focal length decreases, the defect of aberration in the lenses starts increasing. Due to this, the images formed by them become unclear. In reality, a single convex lens cannot achieve a magnification of more than 3, but a lens without an aberration defect can achieve a much higher magnification (about 10).
APPEARS IN
संबंधित प्रश्न
Explain the basic differences between the construction and working of a telescope and a microscope
If this telescope is used to view the moon, what is the diameter of the image of the moon formed by the objective lens ? the diameter of the moon is 3.48 × 106 m and the radius of lunar orbit is 3.8 × 108m.
The total magnification produced by a compound microscope is 20. The magnification produced by the eye piece is 5. The microscope is focussed on a certain object. The distance between the objective and eyepiece is observed to be 14 cm. If least distance of distinct vision is 20 cm, calculate the focal length of the objective and the eye piece.
How can the resolving power of a compound microscope be increased? Use relevant formula to support your answer.
Does the magnifying power of a microscope depend on the colour of the light used? Justify your answer.
Draw a ray diagram showing image formation in a compound microscope ?
Suggest two ways by which the resolving power of a microscope can be increased?
Distinguish between myopia and hypermetropia. Show diagrammatically how these defects can be corrected.
An object is placed at a distance u from a simple microscope of focal length f. The angular magnification obtained depends
A man is looking at a small object placed at his near point. Without altering the position of his eye or the object, he puts a simple microscope of magnifying power 5 X before his eyes. The angular magnification achieved is
A simple microscope is rated 5 X for a normal relaxed eye. What will be its magnifying power for a relaxed farsighted eye whose near point is 40 cm?
Consider the following two statements :-
(A) Line spectra contain information about atoms.
(B) Band spectra contain information about molecules.
Can the image formed by a simple microscope be projected on a screen without using any additional lens or mirror?
A lady uses + 1.5 D glasses to have normal vision from 25 cm onwards. She uses a 20 D lens as a simple microscope to see an object. Find the maximum magnifying power if she uses the microscope (a) together with her glass (b) without the glass. Do the answers suggest that an object can be more clearly seen through a microscope without using the correcting glasses?
compound microscope consists of two convex lenses of focal length 2 cm and 5 cm. When an object is kept at a distance of 2.1 cm from the objective, a virtual and magnified image is fonned 25 cm from the eye piece. Calculate the magnifying power of the microscope.
In the case of a regular prism, in minimum deviation position, the angle made by the refracted ray (inside the prism) with the normal drawn to the refracting surface is ______.
On increasing the focal length of the objective, the magnifying power ______.
With the help of a ray diagram, show how a compound microscope forms a magnified image of a tiny object, at least distance of distinct vision. Hence derive an expression for the magnification produced by it.
| A compound microscope consists of two converging lenses. One of them, of smaller aperture and smaller focal length, is called objective and the other of slightly larger aperture and slightly larger focal length is called eye-piece. Both lenses are fitted in a tube with an arrangement to vary the distance between them. A tiny object is placed in front of the objective at a distance slightly greater than its focal length. The objective produces the image of the object which acts as an object for the eye-piece. The eye-piece, in turn, produces the final magnified image. |
The magnification due to a compound microscope does not depend upon ______.
