Question 13Navigation General

The correct answer is B) Iron spheres mounted on the binnacle. The iron spheres mounted on the binnacle are used to compensate for induced magnetism in the horizontal soft iron of a vessel. This is known as the Flinders bar compensation system. The iron spheres are positioned in such a way that they produce a magnetic field that counteracts the induced magnetism in the horizontal soft iron, thereby minimizing the deviation of the compass. The other options are incorrect because: A) The Flinders bar is a separate device used for this purpose, not the iron spheres themselves. C) Magnets in trays inside the binnacle are not used for this type of compensation. D) A single vertical magnet under the compass would not effectively compensate for the induced magnetism in the horizontal soft iron.