A microscope has an objective of focal length 2 cm , eyepiece of focal length 4 cm and the tube leng

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

Professor PC Thomas Classes · Answer

(d) : Focal length of objective lens, $f_0=2 \mathrm{~cm}$ Focal length of eyepiece lens, $f_e=4 \mathrm{~cm}$ Distance of distinct vision, $D=25 \mathrm{~cm}$  \ $ \begin{aligned} & m=\frac{L}{f_0} 	imes \frac{D}{f_e}=\frac{40}{2} 	imes \frac{25}{4} \ & m=125 \end{aligned} $