Resolving power of a telescope increases with

Options

A. Increase in wavelength of incident light
B. Increase in wavelength of incident light
C. Increase in diameter of objective lens
D. None of these

Answer

To determine how the resolving power of a telescope increases, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Resolving Power**:
The resolving power (RP) of a telescope is defined as its ability to distinguish between two closely spaced objects. It is given by the formula:
\[ RP = \frac{A}{1.22 \lambda} \]
where \( A \) is the diameter of the objective lens and \( \lambda \) is the wavelength of the light used.

2. **Analyzing the Formula**:
From the formula, we can see that:
- The resolving power \( RP \) is directly proportional to the diameter \( A \) of the objective lens.
- The resolving power \( RP \) is inversely proportional to the wavelength \( \lambda \) of the light.

3. **Effect of Wavelength**:
Since \( RP \) is inversely proportional to \( \lambda \), if the wavelength increases, the resolving power decreases. Therefore, an increase in wavelength does not lead to an increase in resolving power.

4. **Effect of Diameter**:
Since \( RP \) is directly proportional to \( A \), if the diameter of the objective lens increases, the resolving power increases. Thus, increasing the diameter of the objective lens will enhance the telescope's resolving power.

5. **Conclusion**:
Based on the analysis, we conclude that the resolving power of a telescope increases with an increase in the diameter of the objective lens.

### Final Answer:
The resolving power of a telescope increases with the increase in the diameter of the objective lens.

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