What are magnetic field lines? List two characteristic properties of these lines.

Explanation

### Step-by-Step Solution

1. **Definition of Magnetic Field Lines**:
- Magnetic field lines are imaginary lines that represent the strength and direction of the magnetic field around a magnet. They help visualize how the magnetic field behaves in the space surrounding the magnet.

2. **Characteristic Property 1**:
- Magnetic field lines originate from the North Pole of a magnet and terminate at the South Pole. This means that the lines show the direction of the magnetic field, flowing from the north to the south.

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