An object is placed at a distance u from a simple microscope of focal length f. The angular magnification obtained depends

Options

A. on f but not on u
B. on u but not on f
C. on f as well as u
D. neigher on f nor on u

Answer

To determine how the angular magnification (M) of a simple microscope depends on various factors, we can analyze the situation step by step.

### Step 1: Understanding Angular Magnification
Angular magnification is defined as the ratio of the angle subtended by the image at the eye when viewed through the microscope to the angle subtended by the object at the unaided eye.

### Step 2: Formulas for Angular Magnification
For a simple microscope, there are two scenarios to consider:
1. When the image is formed at the near point (D).
2. When the image is formed at infinity.

The formulas for angular magnification in these two cases are:
- When the image is at the near point (D):
\[ M = 1 + \frac{D}{f} \]
- When the image is at infinity:
\[ M = \frac{D}{f} \]

### Step 3: Identifying Dependencies
From the formulas derived:
- In both cases, the angular magnification (M) depends on the focal length (f) of the microscope.
- It also depends on the near point distance (D), which is typically taken as a constant value for a normal human eye (approximately 25 cm).

### Step 4: Conclusion
Thus, we can conclude that the angular magnification obtained from a simple microscope depends primarily on:
1. The focal length (f) of the microscope.
2. The near point distance (D), which is a constant for normal vision.

### Final Answer
The angular magnification obtained depends on the focal length of the microscope and the near point distance.

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