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Question
An object is placed at a distance u from a simple microscope of focal length f. The angular magnification obtained depends
Options
on f but not on u
on u but not on f
on f as well as u
neither on f nor on u
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Solution
on f as well as u
The angular magnification is the ratio of the angle subtended by the image to the angle subtended by the object on an unaided eye.
In a simple microscope,
m=`(h/u)/(h/D)`
Here,
u = Object distance from the lens
D = Image distance from the lens
h = Height of the object
In normal adjustment, the object is placed at a distamce equal to focal length(f) from the lens and then magnification is given by m = D/f.
For u < f, m = D/f +1.
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