Which of the following is not vector quantity ?

Options

A. Momentum
B. Weight
C. Potential energy
D. Nuclear spin

Answer

To determine which of the following is not a vector quantity, we need to analyze each option based on the definition of vector quantities. A vector quantity has both magnitude and direction.

1. **Momentum**:
- Momentum is defined as the product of mass and velocity.
- It has both a magnitude (the value of mass times velocity) and a direction (the direction of the velocity).
- Therefore, momentum is a vector quantity.

2. **Weight**:
- Weight is the force exerted by gravity on an object.
- It has a magnitude (the weight value) and a direction (towards the center of the Earth).
- Thus, weight is also a vector quantity.

3. **Potential Energy**:
- Potential energy is the energy stored in an object due to its position or configuration.
- It has a magnitude (the value of energy) but does not have a specific direction associated with it.
- Therefore, potential energy is not a vector quantity.

4. **Nuclear Spin**:
- Nuclear spin refers to the intrinsic angular momentum of atomic nuclei.
- It has both a magnitude and a direction.
- Hence, nuclear spin is a vector quantity.

Based on this analysis, the option that is not a vector quantity is **Potential Energy**.

### Summary of the Solution:
- **Momentum**: Vector quantity (has magnitude and direction).
- **Weight**: Vector quantity (has magnitude and direction).
- **Potential Energy**: Not a vector quantity (has magnitude but no direction).
- **Nuclear Spin**: Vector quantity (has magnitude and direction).

### Final Answer:
**Potential Energy** is not a vector quantity.

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