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WorksheetsApplied Physics-Magnets & DC Motors Review
Total questions: 40
Worksheet time: 3hrs 49mins
Magnetic Domain
The north and south ends of a magnetic object, where the magnetic force is strongest.
A material that shows strong magnetic properties.
A grouping of atoms that have their magnetic fields aligned.
The area of magnetic force around a magnet
Any material that attracts iron and materials that contain iron.
Mognet
Magnet
Nucleus
Magnetic Force
Ferromagnetic Material
A material that shows strong magnetic properties.
Magnet made from material that easily loses its magnetism.
A magnet made from material that keeps its magnetism for a long time.
A grouping of atoms that have their magnetic fields aligned.
unaligned
Magnetic domain
Magnetic alignment
aligned
If you put a magnet to a nail what does the nail become
Permanent magnet
Temporary magnet
What do like sides of a magnet do.
pull together
repel
Attract
No nothing
A North and South pole of a magnet will?
Attract
repel
push away
do nothing
What is the shape of a magnetic field around a wire?
What is the shape of a magnetic field around the Earth?
What is the shape of a magnetic field around a coil?
What is the shape of a magnetic field around a bar magnet?
The area of magnetic force around a magnet is known as its _____________.
magnetic field
magnetic declination
magnetic fan lines
magnetic tan lines
What will happen when these magnets are brought close together?
They will attract each other
Both magnets will turn to the left
They will repel each other
Both magnets will turn to the right
What is this rule?
left hand rule
right hand rule
electricity can be used to create a magnet
true
false
Where is the magnetic field strongest around a bar magnet?
in the middle
at the poles
same everywhere
where the field lines are far apart
Increasing the number of coils in an electromagnet will _________ the power of the magnet.
decrease
increase
not affect
What type of core is best for electromagnets?
Steel
Iron
Plastic
Copper
What conclusion can you draw from this graph?
As current increases, magnetic strength decreases.
As current increases, magnetic strength increases.
As current decreases, magnetic strength increases.
There is no relationship between current and magnetic strength.
What is/are the difference(s) between a magnet and an electromagnet? (two correct choices)
An electromagnet can be turned on/off.
A magnet can be turned off.
An electromagnet is stronger.
How does armature winding affect the performance of a DC motor?
Armature winding has no impact on DC motor performance
Armature winding affects the speed, torque, and efficiency of a DC motor.
Armature winding increases the weight of the DC motor
Armature winding affects only the color of the DC motor
What role does the brush play in a DC motor?
The brush provides lubrication for the motor
The brush generates heat to power the motor
The brush conducts electrical current between stationary and rotating parts.
The brush controls the speed of the motor
Magnetic field lines flow
north to south
north to north
south to south
south to north
Which of these are found
in a simple DC motor?
slip-ring
brushes
split-ring commutator
magnet
power supply
What is the primary function of a split ring commutator in a DC motor?
To increase the motor's speed
To reverse the direction of current flow in the armature
To convert AC to DC
To reduce the magnetic field interaction
How does the magnetic field influence the operation of a DC motor?
It does not affect the motor
It creates a force that causes the rotor to turn
It reduces the electrical resistance of the motor
It increases the output voltage of the motor
What is the role of current in generating torque in a DC motor?
Current heats up the motor coils
Current magnetizes the rotor
Current interacts with the magnetic field to produce torque
Current lubricates the motor components
What happens when the direction of current in a DC motor's armature is reversed?
The motor stops
The motor's speed doubles
The rotational direction of the motor reverses
The motor produces more heat
What is the effect of increasing the current in a DC motor's armature?
Decreases torque
Increases torque
No effect on torque
Decreases motor speed
Which component of a DC motor is primarily responsible for conducting electrical current to the motor's rotating armature?
Bearings
Brushes
Shaft
Casing
What is the primary purpose of the magnetic field in a DC motor?
To provide structural support to the motor
To cool down the motor
To interact with the armature current to produce motion
To insulate the motor components
In the context of DC motors, what does the term "armature" refer to?
The outer casing of the motor
The coils that generate magnetic field
The rotating part of the motor
The stationary part of the motor
What is the result of increasing the strength of the magnetic field in a DC motor?
Decreases the torque
Increases the torque
No change in torque
Decreases the current
