What is the magnification of simple microscope having focal length 5 mm?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 51
A simple microscope is a convex lens of short focal length f used as a magnifier. When the final image is formed at the least distance of distinct vision \( D = 25\,\mathrm{cm} \), its magnification is
\( \displaystyle m = 1 + \frac{D}{f} \)
\( D = 25\,\mathrm{cm} = 250\,\mathrm{mm} \)
\( \displaystyle m = 1 + \frac{250\,\mathrm{mm}}{5\,\mathrm{mm}} = 1 + 50 = 51 \)