Draw a labelled ray diagram of a compound microscope, when final image is formed at infinity. On which factors does the magnifying power of the microscope depend?
Show Hint
The magnifying power of a compound microscope is influenced by the focal lengths of the objective and eyepiece lenses, as well as the length of the microscope tube.
Step 1: Ray Diagram of a Compound Microscope.
A compound microscope consists of two lenses: the objective lens and the eyepiece. The object is placed just beyond the focal point of the objective lens, and the image formed by the objective lens is then used as the object for the eyepiece. The final image is formed at infinity.
Here is the ray diagram of the compound microscope when the final image is at infinity:
Step 2: Factors Affecting the Magnifying Power.
The magnifying power \( M \) of a compound microscope depends on the focal lengths of both the objective lens and the eyepiece. The magnifying power is given by:
\[
M = \frac{D}{f_o} + \frac{L}{f_e}
\]
where \( D \) is the near point distance (typically taken as 25 cm), \( f_o \) is the focal length of the objective lens, \( f_e \) is the focal length of the eyepiece, and \( L \) is the length of the microscope tube. The magnifying power increases with shorter focal lengths of the lenses.
Step 3: Conclusion.
The magnifying power of the microscope depends on the focal lengths of the objective and eyepiece lenses, as well as the length of the microscope tube.
