Quiz 2 (02) Flashcards
Name the filter that has two stop bands?
Band-pass filter
The gain of the first order low pass filter
Decreases at the rate 20dB/decade
An electrical filter is a
Frequency-selective circuit
Filters are classified as
Analog or digital, Passive or active, Audio or radio frequency
If a capacitor is placed in the feedback path of an op-amp circuit, then the circuit can act as
Integrator
Which oscillator is characterized by a split capacitor in its tank circuit?
Colpitts oscillator
Among the following, which is a fixed frequency oscillator?
Crystal oscillator
The oscillator that gives good frequency stability is ____________?
Crystal oscillator
Oscillation requires:
A stage with gain
Colpitts oscillator can be recognized by:
A split capacitance in the tuned circuit
In an oscillator circuit, the feedback should be:
Just enough to sustain oscillation
An oscillator might fail to start for any if the following reasons except:
In-phase feedback
The advantage of a crystal-controlled oscillator over a VFO is:
Low drift
The acoustic feedback in a public-address system
Serves no useful purpose
Because of the small size of ICs compared with equivalent circuits made from discrete
components:
Higher switching speeds are attainable
Which of the following is not an advantage of ICs over discrete components?
Greater power capability
Which of the following component is generally not practical for fabrication in an IC?
Inductors
An op amp usually employs negative feedback to:
Control the gain
In which of the following devices would you be least likely to find an integrated circuit as the main component?
A radio broadcast transmitter’s final amplifier
Which type of IC is used to determine whether voltage levels are the same or not?
A comparator
The value of the decimal number 23 in binary form is:
10111
The binary number 110001 represents the digital number:
49
If X is high, what is the state of X NOR Y?
Low
If X and Y are both high, what is the state of X NAND Y?
Low
If X is high and Y is low, what is the state of X NOT Y?
This logic statement makes no sense
If X = 1 and Y = 1, then X +YZ is:
Always 1
If X = 0 and Y = 1, then X(Y + Z) is:
Always 0
A logic circuit has four inputs W, X, Y, and Z. how many possible input combinations are
there?
16
What is the function of the comparators in the 555 timer circuit?
to compare the input voltages to the internal voltage divider
The ________ is defined as the time the output is active divided by the total period of the
output signal
duty cycle
The 555 timer pin 1 has
Ground
The standard 555 package includes
2 comparators
The 555 timer pin 2 has
Trigger
In 555 timer, reset is present at pin
4
What is the resolution of a digital-to-analog converter (DAC)?
It is the smallest analog output change
A crystal demonstrates the ________ effect when a mechanical force across the crystal causes
a small voltage to be generated.
piezoelectric
Determine the time period of a monostable 555 multivibrator
T = 1.1RC
What is the difference between an astable multivibrator and a monostable multivibrator?
The astable is free running
A monostable 555 timer has the following number of stable states:
1
The monostable multivibrator circuit is not an oscillator because ________.
it requires a trigger to obtain an output signal
The difference between analog voltage represented by two adjacent digital codes, or the analog step size, is the:
resolution
What is the major advantage of the R/2R ladder digital-to-analog (DAC), as compared to a binary-weighted digital-to-analog DAC converter?
It only uses two different resistor values.
Voltage regulators keep a constant ________ output voltage when the input or load varies within limits.
dc
The 7812 regulator IC provides ________.
12 V
The 7912 regulator IC provides ________ .
-12 V
What is the purpose of an additional RC filter section in a power supply circuit?
Decrease the ac voltage component
In which period is the capacitor filter charged in a full-wave rectifier?
The time during which the diodes are conducting
How many diodes conduct in the full-wave bridge rectifier while the capacitor is being
charged?
2
How many terminals does a 7800 series IC regulator have?
3
Across which of the following components of a power supply does the average (dc) voltage exist?
Capacitor filter
