Advertisements
Advertisements
Question
A convex lens of a focal length 5 cm is used as a simple microscope. Where should an object be placed so that the image formed by it lies at the least distance of distinct vision (D = 25 cm)?
Solution
f = 5 cm
v = - 25 cm
We know that, `1/"v" - 1/"u" = 1/"f"`
`=> -1/25 - 1/"u" = 1/5`
`=> -1/"u" = 1/25 + 1/5`
`=> 1/"u" = -((1+5)/25) = - 6/25`
`therefore "u" = - 25/6 "cm" = - 4.16` cm
APPEARS IN
RELATED QUESTIONS
A compound microscope consists of an objective lens of focal length 2.0 cm and an eyepiece of focal length 6.25 cm separated by a distance of 15 cm. How far from the objective should an object be placed in order to obtain the final image at
- the least distance of distinct vision (25 cm), and
- infinity?
What is the magnifying power of the microscope in each case?
An angular magnification (magnifying power) of 30X is desired using an objective of focal length 1.25 cm and an eyepiece of focal length 5 cm. How will you set up the compound microscope?
Suggest two ways by which the resolving power of a microscope can be increased?
An object is placed at a distance u from a simple microscope of focal length f. The angular magnification obtained depends
In which of the following the final image is erect?
(a) Simple microscope
(b) Compound microscope
(c) Astronomical telescope
(d) Galilean telescope
An object is to be seen through a simple microscope of focal length 12 cm. Where should the object be placed so as to produce maximum angular magnification? The least distance for clear vision is 25 cm.
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?
Can the image formed by a simple microscope be projected on a screen without using any additional lens or mirror?
An eye can distinguish between two points of an object if they are separated by more than 0.22 mm when the object is placed at 25 cm from the eye. The object is now seen by a compound microscope having a 20 D objective and 10 D eyepiece separated by a distance of 20 cm. The final image is formed at 25 cm from the eye. What is the minimum separation between two points of the object which can now be distinguished?
Draw a ray diagram of compound microscope for the final image formed at least distance of distinct vision?
