Which of the following is responsible for the earth's magnetic field?

Options

A. Convective currents in earth's core.
B. Diversive current in earth's core.
C. Rotational motion of earth.
D. Translational motion of earth.

Explanation

To determine which of the options is responsible for the Earth's magnetic field, we can analyze each option step by step:

### Step-by-Step Solution:

1. **Understand the Earth's Core Composition**:
- The Earth's core is primarily composed of molten iron and nickel. This molten state is crucial for the generation of magnetic fields.

2. **Identify the Movement in the Core**:
- The core is not static; it experiences movement. The molten iron in the outer core moves due to convection currents. These currents are caused by the heat from the inner core and the rotation of the Earth.

3. **Recognize the Role of Convective Currents**:
- The convective currents in the molten outer core create electric currents. According to the principles of electromagnetism, moving electric charges generate magnetic fields.

4. **Evaluate the Options**:
- **Option 1: Convective current in the Earth's core** - This is the correct answer as it directly relates to the generation of the Earth's magnetic field.
- **Option 2: Divergent current in the Earth's core** - This is not a recognized term in the context of Earth's magnetic field.
- **Option 3: Rotational motion of Earth** - While the Earth's rotation does play a role, it is the convective currents that directly generate the magnetic field.
- **Option 4: Translation motion of Earth** - This motion does not contribute to the magnetic field.

5. **Conclusion**:
- The primary source responsible for the Earth's magnetic field is the convective currents in the Earth's core.

### Final Answer:
The correct option is **Convective current in the Earth's core**.

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