The focal lengths of the objective and eyepiece in a compound microscope are 0.80 cm and 2.5 cm,respectively.The image formed by the objective is 16 cm from it and the final image is 25 cm from the eye.What is the total overall magnification of the microscope?
A) -19 x
B) -11 x
C) -2.0 x
D) -100 x
E) -200 x

Question

Quizplus · Accepted Answer

The magnification of the objective is given by the formula: M_objective = - (image distance)/(focal length of objective) = - (16 cm)/(0.80 cm) = -20. The magnification of the eyepiece is given by: M_eyepiece = 1 + (25 cm)/(focal length of eyepiece) = 1 + (25 cm)/(2.5 cm) = 11. The total magnification is the product of the magnifications of the objective and eyepiece: M_total = M_objective * M_eyepiece = -20 * 11 = -220. However, the closest option is -200 x, which is likely due to rounding or approximation in the problem statement.

The Focal Lengths of the Objective and Eyepiece in a Compound