Which of the following statements is correct for a compound microscope?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → The eyepiece essentially functions like a simple microscope or a magnifier.
A compound microscope has two convex lenses: the objective forms a real, inverted, magnified image of the object, and the eyepiece is used on that image as a magnifier.
Option (1) Both the objective and the eye piece should have large aperture. — Incorrect. The objective has a small aperture; only the eyepiece has a larger one.
Option (2) Both the objective and the eye piece should have large focal lengths. — Incorrect. A high magnification needs short focal lengths for both lenses, since the magnifying power depends on \( 1/f_o \) and \( 1/f_e \).
Option (3) The eyepiece essentially functions like a simple microscope or a magnifier. — Correct. The eyepiece works as a simple microscope on the image formed by the objective, which lies within its focal length.
Option (4) The final image is erect with respect to the original object. — Incorrect. The objective's image is inverted and the eyepiece does not turn it over, so the final image is inverted with respect to the object.
NCERT (2026-27):
The Microscope – “… The lens nearest the object, called the objective, forms a real, inverted, magnified image of the object. This serves as the object for the second lens, the eyepiece, which functions essentially like a simple microscope or magnifier, produces the final image, which is enlarged and virtual.”
The Microscope – “… Clearly, the final image is inverted with respect to the original object.”