- Moving electric charges will interact with...
Your answer:
both electric and magnetic fields
none of these
an electric field
a magnetic field
- Magnetism is due to the motion of electrons as they....
Your answer:
none of these
both around the nucleus and spin on their axes
move around the nucleus
spin on their axes
- The scientist who first discovered a link between electricity and magnetism was....
Your answer:
Michael Faraday
Hans Oersted
Albert Einstein
William Gilbert
- Loops of wire in a motor rotate baecause a...
Your answer:
battery effectively pushes a loop around in the field
magnet attracts stationary electrons in the wire
current exerts a force on the loop, causing it to rotate
magnetic field exerts forces on moving electrons in the loop
- The force on an electron moving in a magnetic field will be the largest when its direction....
Your answer:
is exactly opposite to the direction of the field direction
is at an angle other than 90 degrees to the magnetic field direction
is the same as the magnetic field direction
is perpendicular to the magnetic field direction
- Which force field can increase a moving electron's speed?
Your answer:
electric field
magnetic field
both electric and magnetic fields
none of them
- Which force field can accelerate an electron, but never change its speed?
Your answer:
both electric and magnetic fields
none of them
magnetic field
electric field
- Alternating current is made by...
Your answer:
huge chaemical batteries
none of these
alternating current and voltage
alternating the direction of voltage of the power source
- The frequency of AC current in North America is.....
Your answer:
60 Hz
50 Hz
120 V
30 V
- The person credited with discovering that electricity can be produced from magnetism was
Your answer:
Hans Oersted
Albert Einstein
Michael Faraday
William Gilbert
- The creation of an electric current by a changing magnetic field is known as ...
Your answer:
transformation
electromagnetic induction
stepping-up
generation
- A magnet is moved in and out of a coil of wire connected to a high-resistance voltmeter. If the number of coils doubles, the induced voltage....
Your answer:
halves
is the same
quadruples
doubles
- A magnet is moved in and out of a coil of wire connected to several lamps. If the number of coils is doubled...
Your answer:
it is easier to move the magnet
there is no difference in moving the magnet
it is harder to move the magnet
no answer
- A device that uses electromagnetic induction is a
Your answer:
generator
turbine
doorbell
motor
- The magnetic field strength inside a current-carrying coil will be greater if the coil encloses a....
Your answer:
glass rod
iron rod
wooden rod
vacuum
- The principle reason voltage is induced in the loops of a generator coil is that the...
Your answer:
magnet's strength is changing
loops are rotating, changing the amount of magnetic field within the loops
size of the loops are changing
magnet is rotating
- If the primary coil of a transformer were connected to a DC power supply, the transformer would operate.....
Your answer:
the same as always
only while being connected and disconnected
only if the output is also DC voltage
at very low efficiency
- A transformer works because....
Your answer:
electricity flows from the primary coil to the secondary coil
a changing magnetic field is transferred to a coil via an iron coil
electricity is trnasfered to the a coil via an iron coil
electricity is induced in a rotating coil
- A transformer transforms...
Your answer:
generators into motors
voltage
non-safe forms of energy into safe forms
magnetic field lines
- A step-up transformer increases...
Your answer:
energy
none of these
power
power and energy
- If a transformer increases AC voltage, it will also increase...
Your answer:
none of these
power
current
magnetic field strength
- Almost all energy sold today is of the AC type because....
Your answer:
DC voltages don't last
AC voltage is easy to step up and step down
AC energy was established first
DC energy wastes electricity
- If the number of turns on the secondary coil in a transformer is three times that of the primary coil the current generated in the secondary is.....
Your answer:
three times
one ninth
nine times
one third
- A student notices that a large cylindrical transformer on top of a telephone pole. This transformer takes 6000 V from the power company and steps it down to the 240 V supplied to each house on the street, with the use of a secondary coil containing 100 turns. How many turns are there on the primary coil?
Your answer:
25
60
2500
14,400
- A step-up transformer has a ratio of 1:10. If 100W of power goes into the primary coil, the power coming from the secondary coil is approximately..
Your answer:
100 W
1 W
1000 W
10 W
- Four amps of current exist in the primary coil of the transformer. The voltage across the primary coil is 110 V. What is the approximate power output of the secondary coil?
Your answer:
27.5 W
110 W
880 W
440 W
- Describe the direction of the current flow in the wire that “causes” the wire to experience a magnetic force directed up the plane of the page. (see diagram above)
Your answer:
no answer
no answer
The current is moving to the right
The current is moving to the left
- Describe the direction of the current flow in the coil that will create a magnetic force acting on the wire pushing it out of the plane of the page? (see daigram above)
Your answer:
no answer
top of coil is O’s (out) and bottom X’s (in)
top of coil is X’s (in) and bottom O’s (out)
no answer
- Describe the direction of magnetic force acting on the wire due to the result of the magnetic field (coming out of the page) as shown in the sketch above
Your answer:
into the page
right
left
out of the page
- Describe the direction of the magnetic force on wire A as a result of the current flow in wire B?
Your answer:
right
left
down
up