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WorksheetsElectromagnetism
Total questions: 25
Worksheet time: 8mins
32. To reverse the direction of current in a motor, current is conducted .............
a. through the armature.
b.in the direction of rotation
c.through the brushes to the commutator.
through the commutator to the armature (Wire Coil found),
33. The type of current produced by a battery is .......
direct current.
alternating current.
magnetic current
induced current.
34.What device transforms electrical energy into mechanical energy?
a. an electromagnet
b. an electric motor
c. a generator
a solenoid (wire coil) .
35.A generator transforms ...........
a .potential energy into kinetic energy.
b. mechanical energy into electrical energy
c. magnetic energy into electrical energy
d. friction into electrical energy
To make this electromagnet stronger you could:
use less wire
have fewer wire coils around the nail
have more wire coils around the nail
use a plastic core
When running a current through a wire, what do the blue lines represent?
The wire spinning
A magnetic field that was created
Electrons leaving
Electricity
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.
How can you decrease the magnetic field strength in an electromagnet?
Increase the number of coils.
increase the voltage
decrease the current by increasing the resistance of the coil
all of the above
What we call the relation between Electricity and magnetism?
Magnet
Electromagnetism
Electricity
Magnetic field
what does the Danish scientist Oersted discoverd?
Electromagnetism
Magnetism
Electricity
None
What does a dynamo do?
It changes kinetic energy into movement
It changes kinetic energy into electricity
It changes electric energy into movement
It changes kinetic energy into kinetic movement
Does a washing machine have an electric motor?
Yes
No
Does a DVD player have an electric motor?
Yes
No
. A coil of wire that has a soft iron core and that acts as a magnet when an electric current is in the coil is called a(n)
temporary magnet
permanent magnet
electromagnet
ferromagnet
The magnitude of the induced current produced in a direct current generator can be increased by
decreasing the number of turns of the coil
increasing the distance between the poles of the permanent magnet
decreasing the diameter of the commutator
increasing the speed of rotation
Which of the following devices produces electric current?
generator
stereo speaker
galvanometer
electric motor
The magnetic field that surrounds a magnet exerts _______.
electric current
the magnetic force
air pressure
resistance
Which electromagnet is the strongest?
