Compass Surveying MCQ with answer and solution

Concept

The compass needle points along the magnetic meridian, and bearings read from it are magnetic bearings.

Step-by-step solution

1. A freely suspended magnetic needle settles along the magnetic meridian. 2. So the compass gives the direction of the magnetic meridian. 3. The angle of a survey line measured from this meridian is the magnetic bearing. 4. So the compass gives both magnetic meridian and magnetic bearing.

Explanation

A magnetic needle always points along the magnetic meridian. The compass reads the angle of a line from this meridian, which is the magnetic bearing. So it gives both.

Why the other options are wrong

A: An arbitrary bearing uses a reference line chosen by the surveyor, not the compass needle, so it is not a direct compass measurement. B: The compass also gives the magnetic meridian direction, so 'only' is wrong. C: The compass also gives magnetic bearings, so 'only' is wrong.

Shortcut

Compass needle = magnetic meridian; angle from it = magnetic bearing.

Common mistake

Choosing 'magnetic bearing only' and forgetting that the needle itself shows the magnetic meridian.