- Home
- General Science
Physics -- Optics
16.
An astronomical telescope has an angular magnification of
magnitude 5 for distant objects. The separation between the
objective and the eyepiece is 36 cm. The final image is formed at
infinity. The focal lengths fo of the objective and fe of the eyepiece
are
- A.45 cm and -9 cm respectively
- B.50 cm and 10 cm respectively
- C.7.2 cm and 5 cm respectively
- D.30 cm and 6 cm respectively
- Answer
- Report
Answer : [D]
17.
An astronomical telescope in normal adjustment receives light
from a distant source S. The tube length is now decreased
slightly.
- A.A virtual image of S will be formed at a finite distance.
- B.No image will be formed.
- C.A small, real image of S will be formed behind the eyepiece, close to it.
- D.A large, real image of S will be formed behind the eyepiece, far away from it.
- Answer
- Report
Answer : [A]
18.
In the previous question, if the tube length is increased slightly
from its position of normal adjustment,
- A.a virtual image of S will be formed at a finite distance
- B.no image will be formed
- C.a small, real image of S will be formed behind the eyepiece, close to it
- D.a large, real image of S will be formed behind the eyepiece, far away from it
- Answer
- Report
Answer : [D]
19.
In a compound microscope, maximum magnification is obtained
when the final image
- A.is formed at infinity
- B.is formed at the least distance of distinct vision
- C.coincides with the object
- D.coincides with the objective lens
- Answer
- Report
Answer : [B]
20.
Two coherent monochromatic light beams of intensities I and 4I
are superposed. The maximum and minimum possible intensities
in the resulting beam are
- A.5I and I
- B.5I and 3I
- C.9I and I
- D.9I and 3I
- Answer
- Report
Answer : [C]
|
|
||||||||||||||||||||||||||||
