Aforensic scientist in using a standard biological microscope with 15 objective and 5 eyepiece to examine a hair from a crime scene. how far from the objective in the hair? take a standard tube length of 160mm.

The given data is Magnification, M = 15

Length of the tube , L = 16 cm

The focal length of the lens can be calculated by:

M = L/F

Substituting the value, we get:

15 = 16/f

f = 16/15

f = 1.067 cm

Using the equation of magnification we get,

M = v/u

Substituting the values we get:

15 = v/u

v = 15 u

With the help of lens formula, calculate the object distance:

1/f = 1/v + 1/u

Substituting the value we get,

1/1.067 = 1/15u + 1/u

0.937 = 1.067/u

u = 1.13 cm or 1.1 cm.

Hence, the object distance is 1.1 cm.