What does magnetic variation measure?

• A. The difference between flight levels
• B. The difference between true north and magnetic north
• C. The directional compass setting
• D. The altitude fluctuation

Answer: (B)

Magnetic variation is defined as the angular difference between true north and magnetic north. True north refers to the geographic North Pole, which is a fixed point on the globe, while magnetic north is the direction a compass points to, which can fluctuate based on the location on Earth and the local magnetic field influences.

Understanding magnetic variation is crucial for navigation, as pilots must account for this difference when using magnetic compasses for heading information. Maps and charts typically indicate magnetic variation, allowing pilots to adjust their navigational calculations to ensure accurate course plotting.

The other options do not accurately reflect what magnetic variation measures. For instance, the difference between flight levels pertains to vertical separation, while the directional compass setting does not encompass the concept of variation. Altitude fluctuations are unrelated to the measurement of directional differences between types of north.