In a microscope the objective is having focal length f_ o =2 ~cm and eye-piece is having focal length f_ e =4 ~cm . The tube length is 32 cm. The magnification produced by this microscope for normal adjustment is

Correct answer: 100 For microscope at normal adjustment: M = (L)/(f_o) × (D)/(f_e) where L = 32 cm, f_o = 2 cm, f_e = 4 cm, D = 25 cm M = (32)/(2) × (25)/(4) = 16 × 6.25 = 100

JEE Main 202621 JanuaryMorning Shift

Exam: JEE Main
Year: 2026
Date: 21 January
Shift: Morning Shift
Subject: Physics
Chapter: Ray Optics

JEE Main 2026 · 21 January · Morning Shift · Physics · Ray Optics

In a microscope the objective is having focal length f_ o =2 ~cm...

In a microscope the objective is having focal length

f_{o}=2 \mathrm{~cm}

and eye-piece is having focal length

f_{e}=4 \mathrm{~cm}

. The tube length is 32 cm. The magnification produced by this microscope for normal adjustment is

\_\_\_\_

Correct answer

100

Step-by-step solution

For microscope at normal adjustment:

M = \frac{L}{f_o} \times \frac{D}{f_e}

where

L = 32

cm,

f_o = 2

cm,

f_e = 4

cm,

D = 25

M = \frac{32}{2} \times \frac{25}{4} = 16 \times 6.25 = 100

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