The magnetized needle of a compass lines up with Earth’s magnetic field (with is created from its iron core)
100
Finish the sentence:
Opposite magnetic poles ______________ each other
attract
100
What is the difference between a solenoid and an electromagnet?
A solenoid is a coil of wire with an electric current.
An electromagnet is a solenoid with an iron core.
100
What is a galvanometer?
An instrument that measures small currents.
100
What is a transformer?
Device used to increase or decrease voltage.
200
Where are magnets strongest?
at the poles
200
What is a direct current?
What is an example?
Aa current moving in one direction.
An example is a battery.
200
How does one increase the strength of an electromagnet?
Increase the number of coils, make the coils closer, increase the voltage, increase the strength of the magnetic material for the core.
200
What is the difference between an electric motor and a galvanometer?
In an electric motor, the armature makes a complete rotation and spins continuously
200
What is the difference between a step up and step down transformer?
A step up transformer increases voltage.
A step down transformer decreases voltage.
300
In what direction does a magnetic field move?
north to south
300
What is electromagnetic induction?
The process of generating an electric current from the motion of a conductor through a magnetic field.
300
How can you change the magnetic field of an electromagnet?
reverse the current
300
What allows an electric motor to make a full rotation?
the commutator
300
If I have twice as many secondary coils than primary coils, what can I infer about the voltage?
The output voltage is double the input voltage.
400
If allowed to swing freely, in what direction does a magnet point?
North
400
How can you induce a current?
Move a wire up and down in a magnetic field.
Or move a magnetic field near a wire (or conductor).
400
What is the relationship between electricity and magnetism?
An electric current produces a magnetic field.
A moving magnetic field produces an electric current.
400
What mechanism transforms mechanical energy into electrical energy?
Electric generator
400
If I want the output voltage to be one third the amount of the input voltage, what is the ratio of the primary and secondary coils?
The primary coils are 3x the number of secondary coils.
(or secondary coils are 1/3 the amount of the primary coils)
500
What is magnetic declination?
Angle between the geographic north and magnetic north.
500
In a direct current from a battery, in what direction do the electrons flow?
In what direction does the current flow?
From the negative terminal to the positive terminal.
From the positive terminal to the negative terminal.
500
Explain how a compass is affected by an electromagnet?
A compass will point in a direction other than north only if another magnetic field is present. Since an electromagnet produces a magnetic field, the compass will align with its magnetic field, instead of the Earth's magnetic field.
500
How is an electric motor different than an electric generator?
An electric motor uses electricity to create motion.
An electric generator uses motion to create electricity.
500
How is electromagnetic induction used in a transformer?
In a transformer, an alternating current in one coil (primary coil) produces a changing magnetic field. This induces an electric current in another coil (secondary coil).