Suppose the angular magnification of a compound microscope in normal use is 30.What is the correct explanation of the statement.


In normal use the final image by a compound microscope at D(=25 cm).Angular magnification M=30 means the ratio of visual angle sub tended by the final image of an object at the eye to the visual angle subtended by the same object at the eye(when object is placed at D) is 30.


The formula for compound microscope when in normal usage is $M=(-v_0/u_0)*(1+D/f_e)$ ,So is my approach correct or wrong.

$D$ refers to the distance of least vision.

$u_0$ refers to the distance between the object and the objective lens.

$v_0$ refers to the distance between the image and objective lens.

$f_e$ refers to the focal length of the eyepiece lens.

Any explanations?

  • $\begingroup$ Can someone answer my question?🤓 $\endgroup$ – user184590 Feb 15 '18 at 6:43
  • $\begingroup$ Please define you symbols particularly as what I assume is a multiplication sign confused me. What do you want explained? Do you mean how was that formula derived? $\endgroup$ – Farcher Feb 15 '18 at 7:03
  • $\begingroup$ @Farcher sorry I put X in multiplication symbol.Explain the statement with respect to its formula.I am going to mention the meaning of the symbols now.Please wait. $\endgroup$ – user184590 Feb 15 '18 at 7:05
  • $\begingroup$ @Farcher please answer the question now.I have edited my posted and added the meaning of the variables stated . $\endgroup$ – user184590 Feb 15 '18 at 7:11
  • $\begingroup$ Here is a video which might answer you question? m.youtube.com/… $\endgroup$ – Farcher Feb 15 '18 at 7:14

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