Question

The total magnification produced by a compound microscope is 20 the magnification produced by the ap is 5 the microscope is focused on a certain object the distance between the objective and eyepiece is observed by 14 cm if the least distance of distinct vision is 20 cm calculate the focal length of objective and eyepiece of the microscope

Answer 1

Hello friend,

● Answer -
fo = 3.5 cm
fe = 5 cm

● Explaination -
# Given -
M = 20
Me = 5
D = 20 cm
L = 14 cm

# Solution -
Magnification by the eyepiece is given by -
Me = 1 + D/fe
5 = 1 + 20/fe
fe = 20 / (5-1)
fe = 5 cm

Total magnification is given by -
M = Mo.Me
20 = Mo × 5
Mo = 4

Magnification by objective is given by -
Mo = L/fo
fo = L/M
fo = 14/4
fo = 3.5 cm

Therefore, focal length of objective and eyepiece should be 3.5 cm and 5 cm respectively.

Hope this helps you...