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24 Cards in this Set
- Front
- Back
3-29D1
What is the approximate magnitude of the impedance of a parallel R-L-C circuit at resonance? |
Approximately equal to the circuit resistance
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3-29D2
What is the approximate magnitude of the impedance of a series R-L-C circuit at resonance? |
Approximately equal to the circuit resistance
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3-29D3
How could voltage be greater across reactances in series than the applied voltage? |
Resonance
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3-29D4
What is the characteristic of the current flow in a series R-L-C circuit at resonance? |
Maximum
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3-29D5
What is the characteristic of the current flow within the parallel elements in a parallel R-L-C circuit at resonance? |
Maximum
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3-29D6
What is the relationship between current through a resonant circuit and the voltage across the circuit? |
The voltage and current are in phase
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3-30D1
What is the main advantage of using an op-amp audio filter over a passive LC audio filter? |
Op-amps exhibit gain rather than insertion loss
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3-30D2
What are the characteristics of an inverting operational amplifier (op-amp) circuit? |
It has input and output signals 180 degrees out of phase
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3-30D3
Gain of a closed-loop op-amp circuit is determined by? |
The op-amp’s external feedback network
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3-30D4
Where is the external feedback network connected to control the gain of a closed-loop op-amp circuit? |
From output to the inverting input
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3-30D5
Which of the following op-amp circuits is operated open-loop? |
Comparator
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3-30D6
In the op-amp oscillator circuit shown in Figure 3D6, what would be the most noticeable effect if the capacitance of C were suddenly doubled? |
Frequency would be lower
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3-31D1
What frequency synthesizer circuit uses a phase comparator, look-up table, digital-to-analog converter, and a low-pass antialias filter? |
A direct digital synthesizer
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3-31D2
A circuit that compares the output of a voltage-controlled oscillator (VCO) to a frequency standard and produces an error voltage that is then used to adjust the capacitance of a varactor diode used to control frequency in that same VCO is called what? |
Phase-locked loop
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3-31D3
RF input to a mixer is 200 MHz and the local oscillator frequency is 150 MHz. What output would you expect to see at the IF output prior to any filtering? |
50, 150, 200 and 350 MHz
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3-31D4
What spectral impurity components might be generated by a phase-locked-loop synthesizer? |
Broadband noise
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3-31D5
In a direct digital synthesizer, what are the unwanted components on its output? |
Spurs at discrete frequencies
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3-31D6
What is the definition of a phase-locked loop (PLL) circuit? |
A servo loop consisting of a phase detector, a low-pass filter and voltage-controlled oscillator
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3-32D1
Given the combined DC input voltages, what would the output voltage be in the circuit shown in Figure 3D7? |
-5.5 V
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3-32D2
Which lamps would be lit in the circuit shown in Figure 3D8? |
2, 3, 4, 7 and 8
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3-32D3
What will occur if an amplifier input signal coupling capacitor fails open? |
No amplification will occur, with DC within the circuit measuring normal
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3-32D4
In Figure 3D9, determine if there is a problem with this regulated power supply and identify the problem. |
There is no problem with the circuit
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3-32D5
In Figure 3D10 with a square wave input what would be the output? |
3
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3-32D6
With a pure AC signal input to the circuit shown in Figure 3D11, what output wave form would you expect to see on an oscilloscope display? |
2
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