Question

A standard biological microscope is required to have a magnification of 200Ã. what is the focal length of the objective?

Answer 1

Answer:

The focal length of the objective is L/20.

Explanation:

Given that,

Magnification of the standard biological microscope, m = 200

Let the magnification of the eyepiece is, $m_e=10$

Let $m_o$ is the magnification of objective lens. The formula of the magnification is given by :

$M=m_o\times m_e\\\\200=m_o\times 10\\\\m_o=20$

The formula of the magnification is given by :

$M=\dfrac{L}{f_o}m_e$

L is length of microscope

$f_o$ is focal length of the objective

$f_o=\dfrac{Lm_e}{M}\\\\f_o=\dfrac{10L}{200}\\\\f_o=\dfrac{L}{20}$

So, the focal length of the objective is L/20.