Identify the following forces:
The force which changes the direction of a compass needle.

Explanation

To identify the force that changes the direction of a compass needle, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Compass Needle**: A compass needle is a small magnet that can rotate freely. It has a north and south pole and aligns itself with the Earth's magnetic field.

2. **Identifying the Force**: The force that causes the compass needle to change direction is related to magnetism. When the compass needle is placed in the Earth's magnetic field, it aligns itself along the magnetic field lines.

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