A lens of focal length 45 mm is mounted on a 35 mm camera.The lens aperture is set at f/ 2 and the shutter speed set at 1/2000 s.The aperture diameter,in mm,is closest to:
A)23
B)16
C)19
D)26
E)29

Question

Quizplus · Accepted Answer

The aperture diameter is given by:d = f/Nwhere f is the focal length and N is the f-number.Substituting the given values, we get:d = 45 mm / 2 = 22.5 mmThe closest choice to this value is 23 mm.

A Lens of Focal Length 45 Mm Is Mounted on a 35