A : Average velocity can be zero, but average speed of a moving body can not be zero in any finite time interval.
R : For a moving body displacement can be zero but distance can never be zero.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
C. If Assertion is true statement but Reason is false, then mark (3).
D. If both Assertion and Reason are false statement, then mark (4).

Answer

To solve the question regarding the assertion and reason provided, we will analyze both statements step by step.

### Step 1: Understanding Average Velocity
- **Definition**: Average velocity is defined as the displacement divided by the total time taken.
- **Mathematical Representation**:
\[ \text{Average Velocity} = \frac{\Delta S}{\Delta t} \]
where \(\Delta S\) is the displacement and \(\Delta t\) is the time interval.

### Step 2: Conditions for Average Velocity to be Zero
- **Displacement**: Displacement can be zero if the initial and final positions of the moving body are the same.
- **Example**: If a body moves from point A to point B and then returns to point A, the displacement is zero, thus making the average velocity zero.

### Step 3: Understanding Average Speed
- **Definition**: Average speed is defined as the total distance traveled divided by the total time taken.
- **Mathematical Representation**:
\[ \text{Average Speed} = \frac{S}{\Delta t} \]
where \(S\) is the total distance traveled.

### Step 4: Conditions for Average Speed to be Zero
- **Distance**: The distance can only be zero if the body does not move at all during the time interval.
- **Conclusion**: For a moving body, if it has moved even a little, the distance will be greater than zero, and thus the average speed cannot be zero.

### Step 5: Analyzing the Assertion and Reason
- **Assertion (A)**: "Average velocity can be zero, but average speed of a moving body cannot be zero in any finite time interval."
- This is **correct** because average velocity can be zero if the displacement is zero, while average speed cannot be zero if the body is moving.

- **Reason (R)**: "For a moving body, displacement can be zero but distance can never be zero."
- This is also **correct** because a moving body can return to its starting point (zero displacement) while still having traveled a distance greater than zero.

### Step 6: Conclusion
- Both the assertion and reason are correct, and the reason correctly explains the assertion. Therefore, the correct answer is that both A and R are true, and R is the correct explanation of A.