Understanding the Compass
A compass is a simple yet essential navigational device that helps users find directions. It operates based on the Earth’s magnetic field.

How a Compass Works
- A compass consists of a magnetized needle that is free to rotate on a pivot.
- The needle aligns itself with the Earth's magnetic field, pointing towards the magnetic north.
- This allows users to determine cardinal directions: north, south, east, and west.

Components of a Compass
- **Magnetized Needle:** The core component that moves to indicate direction.
- **Base Plate:** The flat surface on which the needle and other elements are mounted.
- **Degree Scale:** A circular scale marked in degrees, allowing precise navigation.
- **Direction of Travel Arrow:** Indicates the path to follow for reaching a destination.

Why is it Important?
- Compasses are crucial for navigation in various settings, including hiking, boating, and aviation.
- They are reliable in all weather conditions and do not require batteries or electricity.
- Understanding how to use a compass enhances outdoor skills and ensures safety while exploring unfamiliar terrains.

Comparison with Other Instruments
- **Barometer:** Measures atmospheric pressure; not used for direction.
- **Thermometer:** Measures temperature; unrelated to navigation.
- **Altimeter:** Measures altitude; also not directional.
In conclusion, a compass is the correct answer to the question of which device uses a magnetized needle to find directions, owing to its simplicity and effectiveness in navigation.

A compass uses a magnetized needle that aligns with the Earth's magnetic field to show directions.