11 B Section review Flashcards
Which type of magnetic material is used as the core of an electromagnet?
Ferromagnetic bar.
How does it make an electromagnet more efficient?
The solenoid’s strong magnetic field aligns the ferromagnetic domains in the iron, which strengthens the external magnetic field.
What must take place for electromagnetic induction to occur?
Movement of the conductor.
What is the standard AC supply frequency in the United States?
60 Hz
How many times does a fluorescent bulb flicker per second?
120 times
What are three ways to produce steam to power a steam-turbine generator?
Fossil fuel, nuclear energy, and heat from the earth (geothermal).
What are two major structural differences between AC and DC generators as described in this textbook?
The magnets and coils in a DC generator are reversed compared to an AC generator. The DC generator has a split ring commutator which keeps the current going in one direction.
How do these differences affect the way the two machines work?
The DC split ring commutator keeps the current going in one direction while the AC generator current alternates direction.
T or F: The construction of AC generators and AC motors is similar, and the construction of DC generators and DC motors is similar.
True
