Question

Vibration magnetometer before use, should be set
A. In magnetic meridian
B. In geographical meridian
C. Perpendicular to magnetic meridian
D. In any position

Answer 1

Hint: Magnetic meridian is a line on the surface of the earth that runs parallel to the horizontal axis of the magnetic field. However, a complete geodesic curve is formed when the latitude moves from east to west, therefore a compass needle will not remain constant in the magnetic meridian.

Complete step by step solution:
Before use, the vibration magnetometer should be placed in the magnetic meridian because no additional force is applied there. A line inside the earth connecting the magnetic north and south poles is known as a magnetic meridian.

This is the part of the magnetic force lines that run horizontally along the earth's surface. The earth's magnetic lines of force and the magnetic meridian are parallel. With the magnetic north pole situated south of the geographic north pole, which is determined by the globe's rotational axis, the earth behaves very much like a bar magnet.

Hence, the correct answer is option A.

Additional information: A chord that connects one pole to the other is a real meridian. The magnetic meridian is simply parallel to the compass needle, whereas the real meridian is determined through thorough astronomical measurements. This is where the actual meridian differs from the magnetic meridian.

Note: On geodesic curves, magnetic declination is the difference between the true and magnetic meridian on a plane and can be calculated individually for each location. In terms of magnetic declination, a western declination is typically expressed as a negative value while an eastern declination is typically expressed as a positive value.