Advertisements
Advertisements
प्रश्न
The focal lengths of the objective and the eye-piece of a compound microscope are 1.0 cm and 2.5 cm respectively. Find the tube length of the microscope for obtaining a magnification of 300.
Advertisements
उत्तर
Given:
fe = 2.5 cm, fo = 1 cm
Let d be the minimum distance which should be kept away from an eye to see = 25 cm.
Magnification of compound microscope,
`m = m_o xx m_e`
`m = L/f_o xx D/f_e`
Here we need to find L (Length of the microscope), D = 25 cm (near point) and m = 300.
`300 = L/1 xx (25/2.5)`
L = 30 cm
APPEARS IN
संबंधित प्रश्न
A person with a normal near point (25 cm) using a compound microscope with the objective of focal length 8.0 mm and an eyepiece of focal length 2.5 cm can bring an object placed at 9.0 mm from the objective in sharp focus. What is the separation between the two lenses? Calculate the magnifying power of the microscope.
Define the magnifying power of a compound microscope when the final image is formed at infinity. Why must both the objective and the eyepiece of a compound microscope has short focal lengths? Explain.
Does the magnifying power of a microscope depend on the colour of the light used? Justify your answer.
Suggest two ways by which the resolving power of a microscope can be increased?
A compound microscope has an objective of focal length 1.25 cm and eyepiece of focal length 5 cm. A small object is kept at 2.5 cm from the objective. If the final image formed is at infinity, find the distance between the objective and the eyepiece ?
A compound microscope forms an inverted image of an object. In which of the following cases it it likely to create difficulties?
Consider the following two statements :-
(A) Line spectra contain information about atoms.
(B) Band spectra contain information about molecules.
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?
Draw a ray diagram of compound microscope for the final image formed at least distance of distinct vision?
An angular magnification of 30X is desired using an objective of focal length 1.25 cm and an eye piece of focal length 5 cm. How will you set up the compound microscope for the final image formed at least distance of distinct vision?
