Advertisements
Advertisements
प्रश्न
Discuss about astronomical telescope.
Advertisements
उत्तर
- 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
संबंधित प्रश्न
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 simple microscope?
Answer the following question in detail.
What is the limitation in increasing the magnifying powers of a compound microscope?
Discuss about simple microscope and obtain the equations for magnification for near point focusing and normal focusing.
What is the near point focusing?
What are the advantages and disadvantages of using a reflecting telescope?
What is the use of an erecting lens in a terrestrial telescope?
What is myopia?
What is astigmatism? What is its remedy?
Explain the preliminary adjustments of the spectrometer.
A compound microscope has a magnification of 30. The focal length of eye piece is 5 cm. Assuming the final image to be at least distance of distinct vision, find the magnification produced by the objective.
A compound microscope has a magnifying power of 100 when the image is formed at infinity. The objective has a focal length of 0.5 cm and the tube length is 6.5 cm. What is the focal length of the eyepiece.
The near point and the far point for a person are 50 cm and 500 cm, respectively. Calculate the power of the lens the person should wear to read a book held in hand at 25 cm. What maximum distance is clearly visible for the person with this lens on the eye?
A light wave of wavelength λ is incident on a slit of width d. The resulting diffraction pattern is observed on a screen at a distance D. If linear width of the principal maxima is equal to the width of the slit, then the distance D is
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
The speed of light in media 'A' and 'B' are 2.0 × 1010 cm/s and 1.5 × 1010 cm/s respectively. A ray of light enters from medium B to A at an incident angle 'θ'. If the ray suffers total internal reflection, then ______.
An observer looks at a distant tree of height 10 m with a telescope of magnifying power of 20. To the observer the tree appears:
The image formed by an objective of a compound microscope is ______.
