In her biology class,Chris examines an insect wing under a compound microscope that has an objective lens with a focal length of 0.70 cm,an eyepiece with a focal length of 3.0 cm,and a lens separation distance of 16.00 cm.Chris has a near point distance of 22.5 cm.What is the approximate angular magnification of the microscope as Chris views the insect wing?
A)-75
B)-110
C)-140
D)-190
E)-250

Question

Quizplus · Accepted Answer

The angular magnification, M, of a compound microscope is given by the formula:

M = (-d/f) * (D/Fe)

Where:
d = distance between objective and eyepiece lenses 
f = focal length of objective lens 
D = distance between insect wing and objective lens 
Fe = focal length of eyepiece lens

Plugging in the given values: 
d = 16.00 cm 
f = 0.70 cm 
D = 22.5 cm 
Fe = 3.0 cm

M = (-16.00/0.70) * (22.5/3.0) 
M = -228.57

Since angular magnification is always positive, the magnitude of the answer is taken, which is approximately 228.57.

Therefore, the closest answer choice is C (-140).

In Her Biology Class,Chris Examines an Insect Wing Under a Compound