Advertisements
Advertisements
प्रश्न
You are given the following three lenses. Which two lenses will you use as an eyepiece and as an objective to construct a compound microscope?
| Lenses | Power (D) | Aperture (cm) |
| L1 | 3 | 8 |
| L2 | 6 | 1 |
| L3 | 10 | 1 |
Advertisements
उत्तर
For a compound microscope, an objective is so chosen that its aperture is small and focal length is very small whereas an eyepiece is so chosen that its aperture is large and focal length is moderate. Now,
focal length of L1, f1 = 1/3 = 0.33 m
focal length of L2, f2 = 1/6 = 0.166 m
focal length of L3, f3 = 1/10 = 0.1 m
Therefore, from the above calculation of focal length and given aperture, it shows that L1 will be suitable for eyepiece and L3 for objective.
APPEARS IN
संबंधित प्रश्न
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.
When viewing through a compound microscope, our eyes should be positioned not on the eyepiece but a short distance away from it for best viewing. Why? How much should be that short distance between the eye and eyepiece?
How can the resolving power of a compound microscope be increased? Use relevant formula to support your answer.
Draw a ray diagram showing image formation in a compound microscope ?
The separation between the objective and the eyepiece of a compound microscope can be adjusted between 9.8 cm to 11.8 cm. If the focal lengths of the objective and the eyepiece are 1.0 cm and 6 cm respectively, find the range of the magnifying power if the image is always needed at 24 cm from the eye
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?
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?
Define the magnifying power of a microscope in terms of visual angle.
A thin converging lens of focal length 5cm is used as a simple microscope. Calculate its magnifying power when image formed lies at:
- Infinity.
- Least distance of distinct vision (D = 25 cm).
What is meant by a microscope in normal use?
