Advertisements
Advertisements
Question
Discuss about astronomical telescope.
Solution
- An astronomical telescope is used to get the magnification of distant astronomical objects like stars, planets, moon, etc. the image formed by an astronomical telescope will be inverted.
- It has an objective of long focal length and a much larger aperture than the eyepiece.
- Light from a distant object enters the objective and a real image is formed in the tube at its second focal point.
- The eyepiece magnifies this image producing a final inverted image.
Astronomical telescope - The magnification m is the ratio of the angle β subtended at the eye by the final image to the angle ∞ which the object subtends at the lens or the eye.
m = `β/α`
From the diagram,
m = `("h"//"f"_"e")/("h"//"f"_0)`
m = `"f"_0/"f"_"e"`
The length of the telescope is approximate, L = f0 +fe
APPEARS IN
RELATED QUESTIONS
Answer the following question in detail.
Define and describe the magnifying power of an optical instrument.
Answer the following question in detail.
What is the limitation in increasing the magnifying powers of a compound microscope?
Answer the following question in detail.
What is the limitation in increasing the magnifying powers of the astronomical telescope?
What is the near point focusing?
Why is oil-immersed objective preferred in a microscope?
What is the remedy of myopia?
What is presbyopia?
Obtain the equation for resolving the power of the microscope.
Explain the preliminary adjustments of the spectrometer.
Explain the experimental determination of the material of the prism using a spectrometer.
There are four convex lenses L1, L2, L3 and L4 of focal length 2, 4, 6 and 8 cm, respectively. Two of these lenses from a telescope of length 10 cm and magnifying power 4. The objective and eye lenses are respectively
When a convex lens of 12.5 cm focal length is used as a magnifying glass, normal eye can see an object clearly at a distance of 25 cm. The magnifying power of the instrument is ____________.
The magnifying power of a telescope is nine. When it is adjusted for parallel rays, the distance between the objective and eyepiece is 20 cm. The focal length of objective and eyepiece are respectively.
An object viewed from a near point distance of 25 cm, using a microscopic lens with magnification '6', gives an unresolved image. A resolved image is observed at infinite distance with a total magnification double the earlier using an eyepiece along with the given lens and a tube of length 0.6 m, if the focal length of the eyepiece is equal to ______ cm.
Magnification produced by astronomical telescope for normal adjustment is 10 and length of telescope is 1.1 m. The magnification when the image is formed at least distance of distinct vision (D = 25 cm) is ______.
The image formed by an objective of a compound microscope is ______.
