Electrical 7
In an RC parallel circuit, the current through the capacitor will be ___ with the current flow through the resistor
90* out of phase
The symbol for capacitive reactance is
X_c
Dividing a circuit's total applied voltage by the total impedance results in the total
current
In an AC circuit, the current continually changes direction and polarity, causing the ___ to appear to flow through the capacitor
current
A HIPOT is a test set used to test capacitor
dielectric
Polarized capacitors are also known as ___ capacitors
electrolytic
Energy in a capacitor is stored as a(n)
electrostatic charge
Capacitors charge and discharge at a(n) ___ rate
exponential
In an RC parallel circuit, the voltage across the resistor an dthe voltage across the capacitor will be
in phase
Increasing the surface area of the plates will cause the capacitance of a capacitor to
increase
The JAN standard is used to mark a capacitor intended for
military
Polarized capacitors
must be used with DC only
Capacitive reactance is measured in
ohms
A capacitor is constructed by separating two metal conductors called ___ with an insulating material called a ___
plates, dielectric
In a series RC circuit, the angle between the voltage and current is called angle theta (<0). The cosine of the angle is equal to the
power factor
In a capacitor, the amount of dielectric stress is proportional to
the voltage difference betweeen the plates
Power factor (PF) is the ratio of the ___ power to the ___ power
true, apparent
In a series RC circuit, the total impedance is the total current-limiting element in the circuit, and is calculated using the ___ sum of the resistance and reactances in a circuit
vector
When a capacitor and a resistor are connected in series, the time required to charge and discharge the capacitor depends on what is called the
RC time constant
Three factors determine the capacitance of a capacitor. List them.
Surface area of the plates, Distance between the plates, Type of dielectric used
T/F When a capacitor is connected to an AC circuit, current appears to flow through the capacitor due to the fact that the current continualy changes direction and polarity
TRUE
The power in a capacitor is reactive power. The unit of reactive power is the
VAR
Variable capacitors normally have a dielectric of
air
The insulating material between the plates is rated by a value called the
dielectric constant
The capacitive reactance of a capacitor is ___ proportional to the frequency of the applied voltage
inversely
In a purely capacitive circuit, the current will ___ the applied voltage by ___ degrees
lead, 90 degrees
In a capacitor, a small amount of current can flow from the negative plate to the ositive plate through the dielectric material, causing the capacitor to discharge. This is called ___ current
leakage
In an RC parallel circuit, the amount of phase angle shift between the total circuit current and voltage is determined by the ratio of the amount of ___ to the amount of ___
resistance, capacitance
The voltage rating of a capacitor
should never be exceeded
