The potential difference applied to an X-ray tube is increased. As a result, in the emitted radiation,

Options

A. the intensity increases
B. the minimum wavelength increases
C. the intensity remains unchanged
D. the minimum wavelength decreases

Answer

To solve the question regarding the effects of increasing the potential difference in an X-ray tube, we will analyze the relationship between the potential difference, intensity, and minimum wavelength of the emitted radiation.

### Step-by-Step Solution:

1. **Understand the relationship between potential difference and minimum wavelength:**
The minimum wavelength (λ_min) of the emitted X-rays is given by the formula:
\[ \lambda_{\text{min}} = \frac{hc}{eV} \]
where:
- \( h \) is Planck's constant,
- \( c \) is the speed of light,
- \( e \) is the charge of the electron,
- \( V \) is the potential difference (voltage) applied to the X-ray tube.

2. **Analyze the effect of increasing the potential difference:**
If the potential difference \( V \) is increased, the formula shows that \( \lambda_{\text{min}} \) will decrease. This is because \( \lambda_{\text{min}} \) is inversely proportional to \( V \). Therefore, as \( V \) increases, \( \lambda_{\text{min}} \) decreases.

3. **Consider the intensity of the emitted radiation:**
The intensity of the emitted X-rays is related to the number of X-ray photons produced, which depends on the current in the X-ray tube, not directly on the potential difference. While increasing the potential difference can lead to higher energy photons, it does not necessarily increase the intensity (the number of photons). Therefore, the intensity remains unchanged when only the potential difference is increased.

4. **Summarize the results:**
- The minimum wavelength decreases as the potential difference increases.
- The intensity of the emitted radiation remains unchanged.

### Conclusion:
Based on the analysis:
- The minimum wavelength decreases (Option 4 is correct).
- The intensity remains unchanged (Option 3 is correct).

### Final Answer:
The correct options are:
- Option 3: The intensity remains unchanged.
- Option 4: The minimum wavelength decreases.

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