Electrical 8
T/F A PI filter is so-named because the input signal is multiplied by 3.14 to obtain an output signal
FALSE
The bandwith of a filter depends on the ___ of the compnents
Q
T/F A T filter is so-named because a schematic of the circuit looks like a letter T
TRUE
Electronic equipment often needs to separate frequencies. Some frequencies are allowed to pass, while others are rejected. A circuit that separates these frequencies is called a
filter
Filters which offer high opposition to current flow when the frequency is low with little opposition to current flow above a certain frequency is called what type of filter?
high-pass
Power factor correction of motors can be done by connecting a capacitor in parallel with the motor. This is essentially the same thing as creating a ___ circuit which is near resonance
inductive-capacitive-parallel
The most common method of tuning over a broadband of frequencies is by switching from one set of ___ to another, then use a variable ___ to adjust the frequency
inductors, capacitor
In a series RLC circuit, if the circuit contains more inductive VARs than capacitive VARs, then the circuit has a ___ power factor
lagging
In a series RLC circuit, if the current is behind the voltage, the power factor is referred to as
lagging
In a series RLC circuit, if the voltage is ahead of the current, the power factor is refrred to as
lagging
In an RLC parallel circuit, if the circuit contains more inductive VARs than capacitive VARs, then the circuit has a ___ power factor
lagging
In a series RLC circuit, if the circuit contains more capacitive VARs than inductive VARs, then the circuit has a ___ power factor
leading
In an RLC parallel circuit, if the circuit contains more capacitive VARs than inductive VARs, then the circuit has a ___ power factor
leading
Filters which offer little opposition to current flow when the frequency is low is called what type of filter?
low-pass
Some filters eliminate a narrow band of frequencies. These filters are called either band-rejection or ___ filters
notch
Frequencies which are offered much opposition to in a circuit are considered to be
rejected
A band-rejection filter is one that
rejects a range of frequencies while passing frequencies on either side
PI-type filters are so named because they
resemble the Greek letter pi
T filters are so named because they
resemble the letter T
In a series RLC circuit, the point at which X_L and X_c are equal is called
resonance
LC circuit impedance changes with frequency. What type of circuit has high impedance at its resonant frequency and low impedance at all other frequencies
tank
Inductive/capacitive (LC) parallel circuits are often referred to as what type of circuit?
tank circuit
Since components are not made to exact values, some small amount of adjustment is normally required. Adjustable inductors and capacitors are called
trimmer
If the power factor is corrected exactly so that the circuit is purely resistive, then the power factor has a value of
unity
In an RLC parallel circuit, the ___ is the same through all components and the ___ are out of phase
voltage, currents
In an RLC series circuit, the inductive and capacitive reactance are out of phase by ___
180*
A notch filter is also called what type of filter?
band-rejection
Filters that reject a range of frequencies while passing frequencies on either side are called
band-rejection
Filters that pass a certain range of frequencies while rejecting frequencies on either side are called
bandpass
In a parallel LC circuit, the difference in frequencies above and below resonance at which impedance is 0.707 of the maximum is called the ___ of the circuit
bandwidth
The Q of a component is a primary factor in determining what characteristic of a filter?
bandwidth
The difference between the two frequencies at which the current is 0.707 of the maximum is the
bandwidth
Frequencies which are offered little oposition to in a circuit are considered to be
passed
A bandpass filter is one that
passes a range of frequencies while rejecting frequencies on either side
A high-pass filter is one that
passes frequencies above a certain point
A low-pass filter is one that
passes frequencies below a certain point
