A.c. And D.c. Flashcards
What does an a.c. generator consist of?
A rectangular coil that can rotate about an axle between the poles of a magnet.
The ends of the coil are attached to slip rings, against which carbon brushes press.
In an a.c. generator, the frequency of the output voltage is equal to what?
The frequency of the rotation of the coil.
How does the voltage waveform produced by an a.c. generator appear on an oscilloscope screen?
A wavy line.
How does an a.c. generator work?
When the axle is turned, the coil of wire moves through the magnetic field which induces a voltage between the ends of the coil.
What does a.c. stand for?
Alternating current
What is an alternating current?
A current that constantly changes direction.
What does d.c. stand for?
Direct current
What is a direct current?
A current that always flows in the same direction.
What kind of current do batteries provide?
D.c.
What kind of current do generators and some laboratory supply units provide?
A.c.
When drawing a.c. signals on a graph, what rule must be followed?
The signal must cross the time axis.
What does a cross over the time axis indicate on an a.c. graph?
A reversal of current direction.
When drawing direct current signals on a graph, what rule must be followed?
The signal must not cross the time axis.
How can you distinguish between an a.c. graph and a d.c. graph?
An a.c. graph goes below the time axis. A d.c. graph does not.
