Planets producing larger magnetic field have larger

Options

A. Rotational speed
B. Density
C. Mass
D. Size

Answer

To solve the question "Planets producing larger magnetic fields have larger...", we need to analyze the relationship between a planet's magnetic field and its characteristics. The options provided are rotational speed, density, mass, or size.

### Step-by-Step Solution:

1. **Understanding Magnetic Fields**:
- Magnetic fields are produced by moving charged particles. In the case of planets, these charged particles are primarily found in the planet's core.

2. **Role of Rotation**:
- A planet rotates around its axis, and this rotation causes the charged particles in its core to move. The movement of these charged particles generates a magnetic field.

3. **Relation Between Rotation Speed and Magnetic Field**:
- The faster the rotation of the planet, the faster the charged particles in the core move. This increased movement leads to a stronger magnetic field. Thus, there is a direct relationship between the rotational speed of a planet and the strength of its magnetic field.

4. **Conclusion**:
- Based on the above reasoning, we conclude that planets producing larger magnetic fields have larger rotational speeds. Therefore, the correct answer is **rotational speed**.

### Final Answer:
Planets producing larger magnetic fields have larger **rotational speed**.

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