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WorksheetsSummative Assessment #4 Motors and Generators
Total questions: 25
Worksheet time: 19mins
Which of the following refers to a region around a magnet where a magnetic force act?
Domain
Magnetic field
Magnetic force
Perimeter
Which of the following refers to the force between two magnets?
domain alignment
electromagnetic induction
electromagnetism
magnetic force
Which of the following best describes the poles of the magnets that attract each other?
both poles must be N poles
both poles must be S poles
like poles are facing each other
unlike poles are facing each other
Which of the following will make an electromagnet stronger?
add an iron core in the coil
lower the current in the coil
increase the number of loops in the wire
decrease the number of loops in the wire
Which of the following will happen if two like poles are placed near each other?
nothing will happen
the poles will repel each other
the poles will attract each other
the poles will attract first, then repel afterwards
Which of the following scientists discovered that an electric current can produce magnetic field?
Ampere
Oersted
Faraday
Gilbert
Which of the following describes the energy transformation in an electric motor?
electrical to chemical
mechanical to electrical
electrical to mechanical
mechanical to chemical
Which of the following refers to a magnet made of iron, nickel or cobalt?
diamagnet
ferromagnet
paramagnet
If a bar magnet is pushed into a coil, it will induce voltage across the coil. If the same bar magnet is pushed into a coil of wire with twice the number of loops, which of the following holds true?
the same voltage is induced
twice as much voltage is induced
one-half as much voltage is induced
four times as much voltage is induced
Which of the following happens when there is a change in the magnetic field in a closed loop of wire?
current will flow in the loop of wire
electromagnetic induction occurs
voltage is induced in the wire
all of these
Which part of a DC generator changes the direction of current every half-turn?
split rings
slip rings
brushes
battery
Which parts of the DC motor connect the power supply to the split-ring coil?
brushes
magnets
slip rings
commutator
Identify the part labeled 19.
armature
slip rings
brushes
poles
C. brushes
Identify the part labeled 16.
armature
slip rings
brushes
poles
C. brushes
Identify the part labeled 18.
armature
slip rings
brushes
poles
C. brushes
Identify the part labeled 17.
armature
slip rings
brushes
poles
C. brushes
Why does a compass always point north?
The needle is a magnet and it aligns itself with the Earth's magnetic fields
Earth is a magnet and it attracts all metallic object towards the north
Earth's south pole does not have a magnetic pull
All magnets have a north and south pole
What basic principle enables ALL electric generators to operate?
A closed-loop conductor within a changing magnetic field will have an induced electromotive force.
A current-carrying conductor placed within a magnetic field will experience a magnetic force.
Opposite electric charges attract and like charges repel.
Iron is the only element that is magnetic.
In what way is a DC generator different from an AC generator?
The DC generator is operated by an applied voltage.
A DC generator follow Faraday's law while an AC generator works according to Lenz's law.
A DC generator creates an electric current that flows in one direction while the current produced in an AC generator flows in two direction alternately.
A DC generator creates an electric current that flows in a definite direction while the flow of current produced in an AC generator has no definite direction.
Which is true about a generator?
Induced voltage causes the coils of wire to rotate.
Current is supplied to the loop by an external source.
Electric energy is input, mechanical energy is the output.
Mechanical energy is the input, electrical energy is the output
What are the three main parts of an electric motor?
Stator, Battery, and Generator
Rotor, Commutator, and Capacitor
Generator, Stator, and Battery
Stator, Rotor, and Commutator
What is the role of brushes in an electric motor?
To send electrical current to the commutator
To convert mechanical energy
To cool the motor
To increase the speed of the rotor
What type of energy does an electric motor use?
Mechanical energy
Nuclear energy
Chemical energy
Electrical energy
Which of the following is NOT an application of electric motors?
Camera
Vacuum
Solar panel
Blender
Which two appliances use motor to work?
drill and kettle
lamp and mixer
toaster and drill
drill and mixer
