Alternating Current Flashcards
Learn about alternating current
When DC is applied to a circuit containing a capacitor in series with a lamp, the lamp will
Light only during the charging period
When AC is applied to a circuit containing a capacitor in series with a lamp, the lamp will
Light
When DC is applied to a circuit containing no resistance and an inductor in series with a lamp, the lamp will
Light
When AC is applied to a circuit containing no resistance and an inductor in series with the lamp, the lamp will
Light dim for continuous period
Slip rings are used on
AC generators
A commuter is used in
DC generators
An alternator produces which type of waveform
Sinussoidal
How do u find the peak voltage if the RMS (root mean square) is 200V
200/0.707=282V
Why is a commuter used in a DC generator
To provide DC output
With in the ESB generation stations, 3 phase generators produce voltage at
10,000V AC 50 Hz
An alternating current is best defined by a graph which will indicate the
Sinussoidal waveform
The number of cycles of an alternating system traced out each second is called
Frequency
The periodic time of a AC system is the
Time taken to complete one cycle
The frequency of an AC system is measured in
Hertz
What is the name of the rings that rotate in a AC generator
Slip rings
What is attached to to slip rings in a AC generator to make contact with the coil.
Carbon brush’s
In AC generators what is one revolution of a coil referred to as
One cycle
How is the frequency of a supply calculated
F=1/T
F=frequency
T=time (periodic time, one complete cycle)
What it the highest point in a AC wave form called
Peak or maximum value
What is the RMS (root mean value) also know as
Effective value (0.707)
What is the average value also know as
Mean value (0.637)
How do you find the Peak (max)value
RMS(effective) value
0. 707
How do you find the average (mean) value
Peak value X 0.637
How do you find RMS (effective) value
Peak(max) value X 0.707
How do you find the peak(max) value
Average (mean) value
0. 637
The power factor of a purely resistive component connected to a AC supply is ?
Unity
What type of a component has a leading power factor?
A capacitor
In AC the current in a purely capacitive circuit
Lead the voltage by 90 degrees
In AC the current in a purely inductive circuit
Lags the voltage by 90 degrees
What effect limits the current flow in a pure inductive circuit in AC ?
Inductive reactance
