MAGNETISM

Question 1

Vessel laid up for long time

Answer 1

If any question asked first say call compass adjuster.
coefficient magnetism of sub permanent magnetism . coefficient d
retentive error- either in one course long time or one place for long time

Question 2

why mag compass inreliable in higher north

Answer 2

Horizontal component required for compass to be reliable. so in norther pole area there is no horizontal component so its unreliable

DF - Directive force ability to seek north

Question 3

if heeling error bucket chain is finishes

Answer 3

1.Start removing the magnets
2.remove untill last magnet
3.if that also finished the flip the magnet and do opposite like if u were lowering then raise after flipping the magnet and vice versa

Question 4

When does compass is adjusted

Answer 4

1.A period of 2 yrs elapsed since last adjustment and no record of deviation
2.present deviation more than 5+-
3.structural changes or struck by lightening