Advertisements
Advertisements
प्रश्न
A giant refracting telescope has an objective lens of focal length 15 m. If an eye piece of focal length 1.0 cm is used, what is the angular magnification of the telescope ?
Advertisements
उत्तर
Let:
f0 = Focal length of the objective lens = 15 m = 1500 cm
fe = Focal length of the eye lens = 1.0 cm
Angular magnification of the giant refracting telescope is given by
`m_0=|f_0/(f_e)|`
`:.m_0=|1500/1|=1500`
APPEARS IN
संबंधित प्रश्न
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.
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?
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?
Suggest two ways by which the resolving power of a microscope can be increased?
Can the image formed by a simple microscope be projected on a screen without using any additional lens or mirror?
The magnifying power of a converging lens used as a simple microscope is `(1+D/f).` A compound microscope is a combination of two such converging lenses. Why don't we have magnifying power `(1+D/f_0)(1+D/f_0)`?In other words, why can the objective not be treated as a simple microscope but the eyepiece can?
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.
How does the resolving power of a microscope change when
(i) the diameter of the objective lens is decreased?
(ii) the wavelength of the incident light is increased ?
Justify your answer in each case.
Draw a ray diagram of compound microscope for the final image formed at least distance of distinct vision?
The near vision of an average person is 25 cm. To view an object with an angular magnification of 10, what should be the power of the microscope?
