Question

What is the magnifying power of a simple microscope of focal length 5 cm, if the image is formed at the distance of distinct vision?

• A. 4
• B. 7
• C. 6
• D. 5

Hint:

The magnifying power of a simple microscope is calculated using the formula \( M = 1 + \frac{d}{f} \), where \( d \) is the distance of distinct vision and \( f \) is the focal length of the lens.

Answer 1

The Correct Option is C

Step 1: Understanding the magnifying power.
The magnifying power \( M \) of a simple microscope is given by: \[ M = 1 + \frac{d}{f} \] where \( d \) is the distance of distinct vision (usually taken as 25 cm), and \( f \) is the focal length of the lens. Here, \( f = 5 \, \text{cm} \).
Step 2: Substituting the values.
Substituting \( d = 25 \, \text{cm} \) and \( f = 5 \, \text{cm} \), we get: \[ M = 1 + \frac{25}{5} = 1 + 5 = 6 \]
Step 3: Conclusion.
Thus, the magnifying power of the microscope is 6, which corresponds to option (C).