Assertion (A): For best contrast between maxima and minima in the interference pattern of Young's double slit experiment, the amplitudes of light waves emerging from the two sources should be equal.
Reason (R): For interference, the sources must be coherent.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is NOT the correct explanation of A
C. A is true but R is false
D. A is false and R is true

Explanation

To analyze the given assertion and reason, we will break down the concepts involved in the Young's double slit experiment and their implications for interference patterns.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that for the best contrast between maxima and minima in the interference pattern, the amplitudes of light waves from the two sources should be equal.
- In the context of interference, when two coherent waves interfere, the intensity of the resulting wave is dependent on the amplitudes of the individual waves. If the amplitudes are equal, the contrast between the bright (maxima) and dark (minima) fringes is maximized.

2. **Understanding the Reason (R)**:
- The reason states that for interference to occur, the sources must be coherent.
- Coherent sources are those that maintain a constant phase relationship. In Young's double slit experiment, the two slits act as coherent sources of light. This coherence is essential for producing a stable interference pattern.

3. **Evaluating the Truth of A and R**:
- Both the assertion and the reason are true statements. The assertion correctly identifies that equal amplitudes enhance contrast in the interference pattern, while the reason correctly states the necessity of coherence for interference.

4. **Determining the Relationship Between A and R**:
- While both statements are true, the reason (R) does not directly explain the assertion (A). The assertion focuses on amplitude equality for contrast, while the reason emphasizes the requirement of coherence for interference. Therefore, R is not the correct explanation for A.

5. **Conclusion**:
- Both A and R are true, but R is not the correct explanation for A. Thus, the correct answer is that both statements are true, but the reason does not justify the assertion.

### Final Answer:
Both Assertion (A) and Reason (R) are true, but R is not the correct explanation of A.

---