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WorksheetsFinal Exam on Magnetic Compasses
Total questions: 124
Worksheet time: 1hrs 27mins
A compass has a _____ which points North.
magnet
lodestone
force
Nothing
The magnets seen here will _____.
repeling
attracting
Nothing
All A, B & C
The strongest part of the magnet is at the magnet's _____.
force
poles
repel
All A, B & C
_____ are magnets that can be turned on and off.
Electromagnets
Permanent magnets
A constant magnetic field
An electric current
Where is a compass placed that cannot determine direction?
Northern latitude
Polar region
Southern latitude
Equator
Where is the compass placed to determine the best direction?
Polar region
Northern latitude
Equator
Southern latitude
Magnets have _____ poles.
two
varying
three
many
Magnets are attracted to objects made of _____.
plastic
paper
iron
copper
At what distance from the rod is the magnetic pole of the magnet located?
1/8
1/10
1/6
1/12
Where is the compass placed on ships for the most reliable direction?
Bridge
Monkey island
Emergency steering gear room
Cabins
A _____ is an instrument that helps you tell direction.
Poles
Electromagnet
Magnetic compass
Clock
An object that has the pulling or pushing force of a magnet is said to be _____.
magnetic
magical
attracting
repeling
When a magnet pulls toward another magnet, we say that these magnets are " " each other.
Attracting
Repeling
Flying
Nothing
Two like poles, like a South and a South, will always _____.
repel
attract
Nothing
All A, B & C
The _____ is the amount of push or pull a magnet has.
north
force
temporary
A or B
_____ magnets can be magnetized, but lose power quickly.
Permanent
Temporary
Batteries
A & B
A push or pull is called a _____.
Force
Compass
Cat Dog
Clock
Magnets are said to _____ if they push away from each other.
repel
attract
Both A & B
Nothing
_____ magnets keep their magnetism.
Electromagnets
Permanent
An electric current
Nothing
A compass has a magnet which points _____.
east
west
south
north
The area around the magnet that has magnetic force is called the _____.
magnetic field
magnetic compass
electric current
magnetic locks
The poles of a magnet are called the _____ pole and the south pole.
north
east
west
south
_____ is a rock that is called a natural magnet.
Charcoal
Lodestone
Quartzite
Nothing
Assuming that the length between two poles of a magnet is 2L, the distance from each pole to its respective end is _____.
L/24
L/12
L
L/6
The line drawing through two poles of a straight magnet is called _____.
Magnetic neutral axis
Magnetic axis
Magnetic Pole
Magnetic line of force
Magnetic neutral axis of a magnet is the place where _____.
concentrates the strongest magnetic force
concentrates the weakest magnetic force
does not exist magnetic force
the magnetic field strength is effectively zero
Characteristic of magnetic line of force is _____.
existing at everywhere
going from South Pole to North Pole
going from North Pole to South Pole
going from magnetic neutral axis of magnet
What is unit of magnetic pole's force?
Ampe
Kilogram
Volt
Dyne
Which formula illustrates the force between two poles?
Field strength at a point on a line passing through the poles of the magnet is calculated by formula _____.
Field strength at a point on a line bisecting the magnet at right angles is calculated by formula _____.
The North pole end of a magnet is usually painted _____.
green
blue
red
yellow
Position of North Magnetic Pole _____.
coincides North Geographical Pole
closes to North Geographical Pole
closes to South Geographical Pole
coincides South Geographical Pole
Magnetic Variation at a certain place on the earth's surface is the horizontal angle contained between _____.
magnetic axis of magnet and magnetic line of force
the true meridian and the direction of the lines of force of the earth's magnetic field at any place.
the true meridian and the direction of the lines of force of the earth's magnetic field at that place
magnetic axis of magnet and and the direction of the lines of force of the earth's magnetic field at that place.
Lines joining places on a chart having the same value of Variation are called ____.
Isogonal Lines
Iso-depth Lines
Magnetic Line of Force
Isoclinals Lines
When a compass needle, under the influence of the earth's magnetic field at a place, points to the left of True North, the Variation is said to be _____.
Northerly
Easterly
Sotherly
Westerly.
When a compass needle, under the influence of the earth's magnetic field at a place, points to the right of True North, the Variation is said to be _____.
Northerly
Easterly
Sotherly
Westerly.
The vertical angle between the horizontal and the magnetic line of force is ____.
The right symbols of the earth's total force and components of that one are _____.
earth's total force (T), earth's Horizontal Force (H), earth's Vertical Force (Z)
earth's total force (M), earth's Horizontal Force (H), earth's Inclination Force (Z)
earth's total force (H), earth's Horizontal Force (Z), earth's Vertical Force (T)
earth's total force (T), earth's Horizontal Force (H), earth's Inclination Force (Z)
Which force of the earth plays a role in orientating compass needle?
earth's total force
earth's Horizontal Force
earth's Vertical Force
All above
The magnetic moment depends on______.
magnetic field longitude
geographical latitude
magnetic field latitude
geographical longitude
The greatest directive force is exerted on the magnetic compass when the _____.
needle is nearly in line with the meridian
vessel is near the magnetic poles
variation is near zero
vessel is at the magnetic equator
If a magnetic compass is fixed on wooden or composite ship, its compass needle will orientate follow_____.
true meridian
magnetic meridian
magnetic latitude
geographical meridian
Which component of geographic field does magnetic meridian coincide with?
Total force of magnetic field of the earth (T)
Horizontal component of T
Vertical component of T
Heeling component of T
If a magnetic compass is positioned in a magnetized material-manufactured ship, its compass needle will orientate follow ____?
True Meridian
Magnetic meridian
Compass Meridian
Any direction
Which is right definition about deviation?
is the angle between compass needle and true meridian
is the angle between magnetic meridian and true meridian
is the angle between compass needle and compass meridian
is the angle between compass needle and magnetic meridian
If the North end of compass needle is deflected to the right of magnetic meridian, deviation is said to be ____?
Easterly
Westerly
Northerly
Southerly
If the North end of compass needle is deflected to the left of magnetic meridian, deviation is said to be ____?
Easterly
Westerly
Northerly
Southerly
Which is right definition about magnetic compass error?
is the angle between magnetic meridian and compass meridian
is the angle between magnetic meridian and true meridian
is the angle between true meridian and compass meridian
is the angle between compass needle and magnetic meridian
Compass needle of a magnetic compass is affected by
force of geomagnetic field
force of ship's magnetic field
None of above two forces
Both of above two forces
Ship's permanent magnetism is caused by .
operation of electrical equipmet and generators onboard shp
the earth's magnetic fied affecting the ship's hard iron during construction
the horizontal component of the earth's magnetic field acting on the horizontal soft iron
the vertical component of the earth's magnetic field acting on the vertical soft iron
What are symbols of components of ship's permanent magnetism (F) on the compass?
(P ) the athwart component, (Q) the horizontal component, (R) the athwart ship component
(M ) the fore and aft component, (N) the athwart ship component, (P) the athwart ship component
(P ) the fore and aft component, (Q) the athwart ship component, (R) the athwart ship component
(M ) the fore and aft component, (N) the athwart ship component, (O) the athwart ship component
The magnetic compass operates on the principle that .
like magnetic poles attract
unlike magnetic poles repel
unlike poles attract
the poles of the compass line up with the geographic poles of the earth
Which would influence a magnetic compass?
Electrical wiring
Iron pipe
Radio
All of the above
Ship's induced magnetism is caused by______?
Magnetized soft iron
Magnetized hard iron
Geomagnetic field
Compass needle
Which elements do induced ability of soft iron depend on?
The amount of soft iron on board the ship
Magnetic latitude
Ship's heading
geomagnetic field strength
Soft iron rods on board are divided into______?
Vertical soft iron, inclined soft iron, fore-and-aft soft iron
Fore-and-aft soft iron, horizontal soft iron, vertical soft iron
Parallel soft iron, vertical soft iron, horizontal soft iron
Bow soft iron, vertical soft iron, longitudinal soft iron
Which types of soft iron does fore-and-aft magnetic force (X) of the ship magnetise?
Horizontal soft iron
Vertical soft iron
Inclined soft iron
Fore-and-aft soft iron
Which types of soft iron does horizontal magnetic force (Y) of the ship magnetise?
Horizontal soft iron
Vertical soft iron
Inclined soft iron
Fore-and-aft soft iron
Which types of soft iron does vertical magnetic force (Z) of the ship magnetise?
Horizontal soft iron
Vertical soft iron
Inclined soft iron
Fore-and-aft soft iron
Which is total force caused by geomagnetic field and ship's magnetic field on the fore-and-aft axis of the ship?
Which is total force caused by geomagnetic field and ship's magnetic field on the athwartship axis of the ship?
Which is modified Poisson's equation on the fore and aft axis?
Which is modified Poisson's equation on the athwartship axis?
How many forces are combined from modified Poisson's equation
4
5
6
7
Which formula shows relationship between horizontal component of geomagnetic field (H), magnetic force on fore and aft axis (X) and force on athwartship axis (Y)?
Which force is created from combination of two components and ?
F1
FA
FB
FC
Which force is created from combination of two components cZ and P?
FA
FB
FC
FD
Which force is created from combination of two components fZ and Q?
FA
FB
FC
FD
Which force is created from combination of two components and ?
FA
FB
FC
FD
Which forces are very small (zero) in followings ones?
F1 and FC
FA and FE
FA and FC
FB and FE
What is the direction of force H in all heading of the ship?
point toward ship's heading
point toward starboard side of the ship
point toward North end of magnetic meridian
point to port side of the ship
What is the direction of force F1 in all heading of the ship?
point toward ship's heading
point toward North end of magnetic meridian
point toward starboard side of the ship
point to port side of the ship
What is the direction of force FA in all heading of the ship?
point toward ship's heading
point toward North end of magnetic meridian
point toward starboard side of the ship
is perpendicular to magnetic meridian
What is the direction of force FB in all heading of the ship?
point toward ship's heading
point toward North end of magnetic meridian
point toward starboard side of the ship
is perpendicular to magnetic meridian
What is the direction of force FC in all heading of the ship?
point toward ship's heading
point toward starboard side of ship's heading
point toward starboard side of the ship
is perpendicular to magnetic meridian
What is the direction of force FD in all heading of the ship?
( = ( ((: ship's heading)
( = ( + 900 ((: ship's magnetic course)
( = 2( ((: ship's magnetic course)
( = 2( + 900 ((: ship's magnetic course)
What is the direction of force FE in all heading of the ship?
( = ( ((: ship's magnetic course)
( = ( + 900 ((: ship's magnetic course)
( = 2( ((: ship's magnetic course)
( = 2( + 900 ((: ship's magnetic course)
What is regulation about value of ( = on board vessel?
( = 0.8 ( 0.9
( = 0.4 ( 0.5
( = 0.5 ( 0.6
( = 0.6 ( 0.7
At which value of ( can't magnetic compass orientate?
( ( 0.3
( ( 0.4
( ( 0.5
( ( 0.6
Which is the least force among followings ones: ?
Which force plays a role as orientation for compass needle?
H
H'
Which of the following forces contains both H and Z components?
A'λH
B'λH and C'λH
D'λH and E'λH
A'λH, D'λH, E'λH
The deviation caused by A'λH is called:
Semicircular deviation
Quadrant deviation
Fixed deviation
Heeling error
The deviation caused by B'λH is characterized by:
Always being perpendicular to the geomagnetic meridian.
Reaching its maximum value twice during a 360° compass rotation.
Being constant regardless of the ship's heading.
Always being zero at 0° and 180° compass headings.
Which force's deviation is represented by the formula below?
A'λH
B'λH
C'λH
D'λH
D'λH and E'λH cause what type of deviation?
Fixed deviation
Semicircular deviation
Quadrant deviation
Heeling error
The basic deviation formula is used to calculate:
Heeling error only
Pitching error only
The final deviation caused by all five deviation forces
The deviation caused by A'λH only
What causes heeling error?
Changes in the ship's speed.
Changes in the ship's heading.
The ship's inclination from an upright position.
Changes in the magnetic field strength.
Pitching error primarily affects which axis of the compass?
The athwartships axis
The fore-and-aft axis
The vertical axis
All axes equally
What is the primary purpose of studying compass deviations?
To understand the history of compass design.
To ensure safe and accurate navigation.
To impress potential employers with advanced knowledge.
To become proficient in advanced mathematical equations.
What is the main role of a magnetic compass in modern navigation?
It's solely for historical purposes and not used actively.
It's the primary tool for directional guidance, acting as a backup to electronic systems.
It's only used in emergencies when electronic systems fail.
It's primarily a decorative element on modern ships.
Which of the following is NOT a major cause of compass errors?
Magnetic deviation
External magnetic variation
Correct calibration of equipment
Environmental and equipment-related errors
Why is analyzing compass deviation complex?
It's a simple process that requires minimal understanding.
Deviations remain constant regardless of the ship's heading.
There are no significant complexities involved.
Deviations change dynamically with the ship's heading, ship construction amplifies errors, and onboard equipment causes magnetic interference.
What is the Passon equation used for?
Calculating the ship's speed.
Representing magnetic deviation.
Determining the ship's latitude.
Predicting weather patterns.
What are the key variables in the Passon equation?
Ship's length and width.
Magnetic forces, heading angle, ship's magnetic signature, environmental magnetic variations.
Water temperature and salinity.
Engine RPM and fuel consumption.
What is the primary use of the Passon equation?
To predict errors for specific headings and create deviation correction curves.
To calculate the ship's exact geographical location.
To determine the age of the ship.
To measure the speed of the ocean current.
What are the components of the fundamental deviation formula?
Ship's name and registration number.
Coefficients representing magnetic effects, heading angles for specific deviations, and the summation of all influencing factors.
Engine type and horsepower.
Crew size and nationality.
What does the fundamental deviation formula do?
Calculates the ship's fuel consumption.
Predicts magnetic deviations by integrating multiple magnetic influences.
Determines the optimal sailing route.
Measures the ship's stability.
What are the limitations and assumptions of the Passon equation?
It's perfectly accurate under all conditions and requires no adjustments.
It assumes constant environmental conditions, requires accurate input data, and may need adjustments for high-latitude navigation.
It's only suitable for small vessels.
It's unreliable and should not be used for navigation.
What are the key takeaways regarding the Passon equation?
It's useless and should be disregarded.
It's useful for quantifying deviation, serves as a basis for advanced navigation calculations, and is a practical tool for mariners and navigators.
It's only useful for theoretical calculations.
It requires specialized training to use.
What is magnetic compass deviation?
The difference between true north and magnetic north.
Error due to the ship's magnetic influence, varying with heading and ship conditions.
The angle between the ship's heading and its destination.
The amount of time it takes for the compass needle to settle.
How is compass deviation measured?
By using a stopwatch to time the needle's movement.
By randomly guessing and hoping for the best.
By swinging the compass, comparing compass readings against known bearings, and updating deviation cards.
By using a special type of satellite.
Why is correcting compass deviation critical?
It makes the compass look better.
It prevents navigational errors, reduces cumulative inaccuracies, and ensures reliable compass readings.
It saves money on fuel.
It improves the ship's appearance.
What are the steps for applying deviation knowledge onboard?
Ignore the deviation and hope for the best.
Record ship heading, check the deviation card, apply the correction, and verify true heading.
Consult a compass expert before setting sail.
Use a different type of navigation system altogether.
What equipment is used to measure deviation?
A telescope and a sextant.
An azimuth circle, a deviation card, and adjustment tools like magnets.
A GPS device and a nautical chart.
A barometer and a thermometer.
What are some challenges in applying the deviation correction?
There are no challenges involved.
Accurate coefficient determination, sensitivity to environmental changes, and it's not always suitable for high-accuracy needs.
It's too expensive to implement.
It requires specialized training that few people possess.
What are the categories of compass deviations?
Positive and negative.
Permanent, induced, and transient.
Small, medium, and large.
North, south, east, and west.
What is the purpose of swinging a compass?
To make it look pretty.
To determine deviation values for different headings.
To clean the compass needle.
To test its magnetic strength.
What are the three steps involved in measuring compass deviations?
Guessing, hoping, and praying.
Swinging the compass, comparing readings, and updating deviation cards.
Using a specialized computer program.
Consulting a navigation expert.
What is the simplified Passon equation used for?
Calculating the ship's displacement.
Determining the ship's speed through the water.
Predicting compass errors considering the ship's heeling and pitching.
Calculating the ship's cargo capacity.
What causes heeling error?
The ship's speed.
The ship's inclination from upright.
Changes in the magnetic field.
The ship's heading.
What causes pitching error?
Changes in the ship's heading.
The ship's fore-and-aft movement (pitching).
Changes in the magnetic field.
The ship's speed.
What is the formula for heeling error?
δH = AsinHd
LAHi = (R + kZ - eZ)i
δQ = Dsin2Hd
δP = Ecos2Hd
What is the formula for pitching error?
LAHi = (R + kZ - eZ)i
LAH= (R + kZ + aZ)i
δQ= Dsin2Hd
δP = Ecos2Hd
What does a deviation card do?
It's a decorative item.
It records compass errors for various headings.
It shows the ship's location.
It calculates the ship's speed.
What is the purpose of using a deviation card?
It's purely for decorative purposes.
It's used to record and apply corrections for compass deviations.
It's used for calculating the ship's fuel efficiency.
It's used for predicting weather patterns.
What is the importance of maintaining up-to-date deviation cards?
It's not necessary; deviation remains constant.
It ensures accurate compass readings and safe navigation.
It's a legal requirement with no practical benefit.
It's only important for large vessels.
What are the key points to remember about compass deviations?
They are simple and easily predictable.
They are dynamic, complex, require systematic correction, and must be integrated with the Passon equation for accuracy.
They are only relevant in calm waters.
They only affect older ships.
What is the main goal of adjusting magnetic compass errors?
To make the compass look aesthetically pleasing.
To ensure safe and precise navigation, complying with maritime regulations, and avoiding hazards from miscalculations.
To impress maritime authorities with advanced technical knowledge.
To simplify the process of course plotting.
Why is compass accuracy important?
It's mainly a matter of tradition and aesthetics.
Accurate compass readings are vital for safe and precise navigation, compliance with maritime regulations, and avoiding hazards.
It makes navigating easier, but safety isn't significantly impacted.
Only large vessels require accurate compasses.
What are magnetic compass errors?
Errors caused solely by faulty equipment.
Deviations from true north caused by magnetic influences that vary with location and onboard factors, requiring regular checks.
Errors that only affect older compass models.
Errors that only occur in high-latitude regions.
What are the main causes of compass errors?
Incorrect charting and mapmaking techniques.
Magnetic variation, magnetic deviation, and external interference.
The age and model of the compass.
Poor weather conditions.
What are the steps to correct compass errors?
Ignore the errors and hope for the best.
Identify the type and magnitude of the errors
