Which of the following is a vector quantity ?

Options

A. Temperature
B. Flux density
C. Magnetic field intensity
D. Time

Answer

To determine which of the following is a vector quantity among temperature, flux density, magnetic field intensity, and time, we will analyze each option based on the definitions of vector and scalar quantities.

### Step-by-Step Solution:

1. **Understanding Vector and Scalar Quantities**:
- A vector quantity has both magnitude and direction.
- A scalar quantity has only magnitude and no direction.

2. **Analyzing Each Option**:
- **Option A: Temperature**:
- Temperature measures how hot or cold something is, but it does not have a direction. Therefore, temperature is a scalar quantity.
- **Conclusion**: Not a vector quantity.

- **Option B: Flux Density**:
- Flux density is often represented as the dot product of two vectors (e.g., magnetic field and area). The result of a dot product is a scalar quantity.
- **Conclusion**: Not a vector quantity.

- **Option C: Magnetic Field Intensity**:
- Magnetic field intensity is defined as the force experienced by a unit magnetic pole at a point in space. It has both magnitude and direction (the direction is the direction of the magnetic field).
- **Conclusion**: This is a vector quantity.

- **Option D: Time**:
- Time is a measure of duration and does not have a direction associated with it. It is a scalar quantity.
- **Conclusion**: Not a vector quantity.

3. **Final Conclusion**:
- Among the options provided, the only vector quantity is **Magnetic Field Intensity (Option C)**.