UPSC CDS Science Physics Questions Part 1

The direction of the magnetic field at any location on the Earth's surface is commonly specified in terms of field declination and field inclination. Magnetic declination is the angle between the local measurement of the magnetic north and true north. The declination is positive when the magnetic north is east of true north. The magnetic inclination is the angle made by a compass needle when the compass is held in a vertical orientation. Positive values of inclination indicate that the field is pointing downward, into the Earth, at the point of measurement.