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9. Ray optics abd optical instruments — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics9. Ray optics abd optical instruments1 Mark
MCQ
The magnifying power of a compound microscope increases when
  • A
    The focal length of objective lens is increased and that of eye lens is decreased
  • B
    The focal length of eye lens is increased and that of objective lens is decreased
  • C
    Focal lengths of both objective and eye-piece are increased
  • ✓
    Focal lengths of both objective and eye-piece are decreased
✓

Answer

Correct option: D.
Focal lengths of both objective and eye-piece are decreased
d
( d)$m \propto \frac{1}{{{f_o}{f_e}}}$

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