NEW
Font size
WorksheetsREVIEW NAV 1
Total questions: 15
Worksheet time: 8mins
Which statement best defines the Earth's magnetic field and its influence on a magnetic compass?
It's a static force from a solid core.
It's a static force from fixed poles.
It's a dynamic force from a liquid core.
It's a recent, man-made phenomenon.
How does the liquid inside a magnetic compass bowl help improve its performance during navigation?
It increases the compass’s buoyancy for floating stability
It provides a clear medium for visual inspection
It dampens the movement for smooth readings
It lubricates the pivot to reduce friction
Why do opposite magnetic poles attract each other according to the principles of magnetism?
Because they repel each other due to field resistance
Because they have no measurable interaction
Because their magnetic fields complement and pull together
Because they sometimes attract and sometimes repel randomly
How is a magnetic compass's alignment with the Earth's poles best described?
North pole aligns with true North Pole.
North pole aligns with magnetic South Pole.
North pole aligns with a fixed magnetic North Pole.
North pole aligns with a shifting magnetic North Pole.
In what way does the binnacle contribute to the accuracy of a ship’s magnetic compass?
It stores navigational charts for reference
It houses and shields the compass from interference
It displays electronic data for engine performance
It measures the ship’s speed during transit
How does a deviation card help mariners navigate accurately using a magnetic compass?
It logs maintenance activities for the compass
It lists compass errors by heading
It serves as an emergency-use document
It shows total magnetic variation for the region
How does the concept of 'annual change' affect magnetic navigation over time?
It causes yearly changes in deviation values
It results from poor compass maintenance
It reflects the gradual shift of Earth’s magnetic poles
It alters compass accuracy every voyage
Why are multiple echoes more common in deep water?
Sound reflects repeatedly off seabed
Stylus speed increases with depth
Gain control resets automatically
Transducer signal becomes weaker
What action ensures depth is measured from the keel, not the transducer?
Set the correct draft offset
Increase the stylus voltage
Adjust the zero line setting
Reposition the display unit
How is UKC determined using echo-sounder data?
Subtract draft from measured depth
Add draft to measured depth value
Multiply depth by ship’s beam size
Divide depth by ship’s length overall
What is the correct way to operate the echo-sounder for UKC?
Disable alarms and increase gain
Adjust stylus speed and chart scale
Use prescribed settings and manual
Reposition transducer and receiver
How should a mariner respond when the echo sounder shows multiple echoes stacked below the seabed line?
Calibration adjustment line
Actual seabed position
Double reflection error
Incorrect frequency setting
How should a navigator correct the compass reading if the variation is 3°W and the current year adds 1°W of annual change?
Add 4°W to the compass reading to obtain the true course.
Subtract 4°W from the compass reading to get the correct course.
Apply 2°E correction since west becomes east after annual change.
Ignore the correction because annual change does not affect safety.
What should a mariner do to apply knowledge of variation and deviation when determining the ship’s true heading?
Adjust the compass course to find the true heading
Align the compass with GPS data
Prevent the ship from rolling and pitching
Eliminate all compass errors permanently
How should a mariner apply proper technique when reading a compass to ensure accurate heading?
By reading at eye level to avoid parallax error
By reducing deviation caused by the ship’s tilt
By canceling annual variation automatically
By aligning the compass with Earth’s equator
