A standard biological microscope is required to have a magnification of 200X. a. When paired with a 10X eyepiece, what power objective is needed to get this magnification? b. What is the focal length of the objective?

power = 20X

focal length = L / 20

Explanation:

Given data

magnification = 200X

eyepiece = 10X

to find out

power objective is needed and focal length of the objective

solution

we know magnification of microscope M is the product of (m1) magnifying power of object and (m2) magnifying power of eyes

that is M = M1 * M2

so M1 = M / M2

put value M = 200 and M2 = 10

M1 = 200/10 = 20

so here power = 20X

and

now we calculate focal length by this formula

M1 = (L/focal length) M2

here L is length of tube put all value

200 = (L/focal length) 10

focal length = L / 20