(a) Draw a labelled ray diagram showing the formation of a final image by a compound microscope at least distance of distinct vision.
(b) The total magnification produced by a compound microscope is 20. The magnification produced by the piece is 5. The microscope is focused on a certain object. The distance between the objective and eyepiece is observed to be 14cm. If least distance of distinct vision is 20cm, calculate the focal length of the objective and the eye piece.

Explanation

### Step-by-Step Solution

**(a) Ray Diagram of a Compound Microscope:**

1. **Draw the Optical Axis**: Start by drawing a horizontal line to represent the optical axis of the microscope.

2. **Draw the Objective Lens**: Place a convex lens (objective lens) on the left side of the optical axis. Label it as "Objective (O)".

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