Practice portal › Ray Optics and Optical Instruments › Optical Instruments

A microscope has an objective of focal length 2 cm, eyepiece of focal length 4 cm and the tube length of 40 cm. If the distance of distinct vision of eye is 25 cm, the magnification in the microscope is

Asked in NEET 2025 · Microscopes

• (1) 100
• (2) 125
• (3) 150
• (4) 250

Step-by-step solution

Why the other options are wrong

• (1) No single slip gives 100; it would need D=20 cm.
• (3) No single slip gives 150; even L/(fₒ)(1+D/(fₑ)) is only 145.
• (4) Divides by the eyepiece focal length but not by the objective's: (LD)/(fₑ)=(40×25)/4=250.

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.