Assertion: If width of one slit in Young's double slit experiment is slightly increased, then maximum and minimum both intensities will increase.
Reason: Intensity reaching from that slit on screen will slightly increase.

Options

A. (a)If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
B. (b)If both Assertion and Reason are true and the Reason is not the correct explanation of the Assertion.
C. (c) If Assertion is true, but the Reason is false.
D. (d) If Assertion is false, but the Reason is true.

Explanation

To solve the question regarding the assertion and reason in the context of Young's double slit experiment, we will analyze both statements step by step.

### Step 1: Understand the Assertion
The assertion states that if the width of one slit in Young's double slit experiment is slightly increased, then both the maximum and minimum intensities will increase.

### Step 2: Understand the Reason
The reason provided is that the intensity reaching from that slit on the screen will slightly increase due to the increase in the width of the slit.

### Step 3: Analyze the Effect of Slit Width on Intensity
In Young's double slit experiment, the intensity of light from a slit is directly related to the width of that slit. If the width of one slit (let's say slit 1) is increased, the intensity \( I_1 \) from that slit will increase because intensity is proportional to the area of the slit (which is width times height).

### Step 4: Formulas for Maximum and Minimum Intensity
The maximum and minimum intensities in the interference pattern can be expressed as:
- Maximum intensity \( I_{\text{max}} = (\sqrt{I_1} + \sqrt{I_2})^2 \)
- Minimum intensity \( I_{\text{min}} = (\sqrt{I_1} - \sqrt{I_2})^2 \)

Where \( I_1 \) and \( I_2 \) are the intensities from the two slits.

### Step 5: Effect on Maximum and Minimum Intensities
If the width of slit 1 increases, then \( I_1 \) increases. This will affect both the maximum and minimum intensities:
- The maximum intensity \( I_{\text{max}} \) will increase because \( \sqrt{I_1} \) increases.
- The minimum intensity \( I_{\text{min}} \) will also increase because \( \sqrt{I_1} \) increases, which affects the difference \( \sqrt{I_1} - \sqrt{I_2} \).

### Step 6: Conclusion
Since both the assertion and reason are true, and the reason correctly explains the assertion, we conclude that the assertion is true and the reason is also true.

### Final Answer
Both the assertion and reason are true, and the reason is the correct explanation of the assertion.