Ch. 11 Flashcards
What are the ring of coils surrounding the rotor called?
Stator
What are machines that convert electrical energy into rotary mechanical motion?
Motors
What are connected to the circuit slip across the face of the commutator as it rotates under earth them?
Electrical brushes
What is modeled using magnetic lines of force?
Magnetic field
What is a transformer that increases output voltage?
Step-up conductors
The removing of these causes the formation of a permanent magnet
External magnetic field
What is a machine that converts the energy of a moving fluid into rotational motion?
Turbine
What are the most common prime mover for commercial electrical generators?
Steam turbines
The location of the earths concentrated magnetic field lines are vertical at the earths surface
Magnetic North Pole
What are certain materials that lose all electrical resistance at extremely low temperatures?
Superconductors
Who were the first people to use magnetic compasses?
Chinese
Who changes magnetism from superstition to science?
William Gilbert
Magnetic lines of force point
Toward the source magnetic pole
Which of the following will not attract or repel each other?
A magnet and a stationary charge
Which of the following will induce a current in a nearby circuit?
A moving electromagnet
Most of the electricity we use in our homes is supplied by a
AC generator
Geothermal energy generation uses what kind of turbine?
Steam
Which of the following is a step-up transformer?
Fir coil– 7 wraps; second coil– 8 wraps
The first practical use of natural magnets was navigations.
True
William Gilbert was the first person to experiment with magnets.
False
Magnetic fields interact with each other just like electric fields.
True
It is possible for a magnet to have only one pole.
False
The strongest magnets are made out of pure substances.
False
Liquid oxygen and gaseous oxygen display different magnetic properties.
True
Magnets strongly attract all metals.
False
Natural magnets, such as lodestones, display ferrimagnetism.
True
Diamagnetic materials do not contain dipoles.
False
Temperature does not have strong affect on a ferromagnetic object.
False
At the geographic North Pole, a compass will point south.
True
A ferromagnetic material above its Curie temperature will behave like a paramagnetic material when it is place Ina magnetic field.
True
A magnet moving back and forth in the center of a coil of wire produces direct current in the wire.
False
A stator is a pair of solenoids.
True
Generators can produce only alternating current.
False
