Question

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 ______.

विकल्प

• 100

• 125

• 150

• 250

Answer 1

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 125.

Explanation:

Given: f₀ = 2cm

f_e = 4 cm

L = 40 cm

D = 25 cm

For the far point case (normal adjustment), the final image is formed at infinity and the magnifying power is given as M.P.

= `L/(f_0) D/(f_e)`

= `40/2 xx 25/4`

= 5 × 25 

= 125