The magnitude of a vector cannot be

Options

A. positive
B. zero
C. negative
D. unity

Explanation

To solve the question "The magnitude of a vector cannot be," we will analyze the options provided and determine which one is correct.

### Step-by-Step Solution:

1. **Understand the Concept of Magnitude:**
- The magnitude of a vector is a measure of its length or size. It is always a non-negative quantity.

2. **Analyze the Options:**
- We have four options to consider:
1. Magnitude
2. Positive
3. Zero
4. Negative
5. Unity

3. **Evaluate Each Option:**
- **Magnitude:** This term itself refers to the size of the vector, which is always a non-negative value.
- **Positive:** The magnitude of a vector can be positive, as it represents a length.
- **Zero:** The magnitude can indeed be zero, which occurs when the vector itself is a zero vector (having no length).
- **Negative:** The magnitude of a vector cannot be negative. Magnitude is defined as a non-negative quantity, and any negative sign in vector notation refers to direction, not magnitude.
- **Unity:** The magnitude can be unity (1), which is a specific positive value.

4. **Conclusion:**
- The only option that is not possible for the magnitude of a vector is "Negative." Therefore, the answer is that the magnitude of a vector cannot be negative.

### Final Answer:
The magnitude of a vector cannot be **negative**.

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