Description : If the input-signal-developing impedance of an amplifier is increased, what is the effect on the gain?
Last Answer : The gain increases.
Description : In the inverting configuration, what is the voltage (for all practical purposes) at the inverting input to the operational amplifier if the input signal is a 1-volt, peak-to-peak sine wave?
Last Answer : 0 volts.
Description : If the single-input, differential-output, differential amplifier has an output signal taken between the two output terminals, what will the peak-to-peak amplitude of this combined output be?
Last Answer : 200 millivolts. A-18. a. Differential amplifier
Description : If the two input signals to a difference amplifier are equal in amplitude but neither in phase nor 180 degrees out of phase, what will the output signal be?
Last Answer : . A different shape than the input signals but larger in amplitude.
Description : If only one input signal is used with a difference amplifier, what will the output signal be?
Last Answer : Equal in shape and frequency to the input signal; larger in amplitude than the input signal; half as large in amplitude as when two input signals were used that were 180 degrees out of phase.
Description : If the two input signals to a difference amplifier are equal in amplitude and 180 degrees out of phase, what will the output signal be?
Last Answer : Equal in shape and frequency to each input signal and larger in amplitude by two times than
Description : . If the two input signals of a difference amplifier are in phase and equal in amplitude, what will the output signal be?
Last Answer : No output (the signals will "cancel out").
Description : The pump signal frequency must be of what value when compared to the input signal of a simple parametric amplifier?
Last Answer : Exactly double the input frequency.
Description : Does an amplifier actually change an input signal? Why or why not?
Last Answer : No, the input signal is unchanged, the output signal is controlled by the input signal but does not effect the actual input signal.
Description : If the output impedance of an amplifier circuit is decreased, what is the effect on the gain?
Last Answer : The gain decreases.
Description : Calculate the noise figure of the receiver whose RF amplifier has an input resistance of 1000Ω and an equivalent shot-noise resistance of 2000Ω, a gain of 25 and load resistance of 125 kΩ. Given that the bandwidth is 1. ... to an antenna with an impedance of 75Ω. A. 30.3 B. 3.03 C. 303 D. .303
Last Answer : A. 30.3
Description : Non-inverting amplifier circuits have _______ (a) Very high input impedance (b) very low input impedance (c) low output impedance (d) none of above
Last Answer : (a) Very high input impedance
Description : When compared to the JFET, what is the input impedance of the MOSFET?
Last Answer : The MOSFET has a higher input impedance.
Description : The input impedance of your test equipment should exceed the impedance of the circuit under test by what ratio?
Last Answer : 10 to 1
Description : What impedance relationship between the output of one circuit and the input of another circuit will provide the maximum power transfer?
Last Answer : Equal impedance.
Description : What compone What components What components can be used to increase the high frequency response of an amplifier?
Last Answer : Peaking coils.
Description : What the three basic components make up the typical magnetic amplifier?
Last Answer : Two saturable reactors and a transformer.
Description : Indicate the false statement. Noise figure is defined as A. the ratio of the S/N power supplied at the input terminal of a receiver or amplifier to the S/N power supplied to the output or ... under test, both working at the same temperature over the same bandwidth and fed from the same source
Last Answer : C. an unwanted form of energy tending to interfere with the proper and easy reception and reproduction of wanted signals
Description : In the basic transistor amplifier discussed earlier, what is the relationship between the polarity of the input and output signals?
Last Answer : The signals are opposite in polarity or 180 degrees out of phase with each other.
Description : The input and output signals of a JFET amplifier have what phase relationship?
Last Answer : They are 180 degrees out of phase.
Description : What is used to bias a magnetic amplifier so that the control winding remains free to accept control (input) signals?
Last Answer : A bias winding and associated circuitry.
Description : If the differential amplifier is configured with a single input and differential outputs, what will the output signals be?
Last Answer : Each output will be a sine wave with a peak-to-peak amplitude of 100 millivolts. The output signals will be 180 degrees out of phase with each other.
Description : What two transistor amplifier configurations are combined in the single-transistor, two-input, single-output difference amplifier?
Last Answer : Common emitter (CE) and common base (CB)
Description : In a nondegenerative parametric amplifier the difference between the input frequency and the pump frequency is called what?
Last Answer : Idler- or lower-sideband frequency.
Description : If the rf amplifier discussed has an 80 milliwatt input, what would be the maximum output?
Last Answer : 800 watts.
Description : When a large signal and a small signal are applied to a lin log amplifier at the same time, what is the effect on the small signal?
Last Answer : Amplification is reduced.
Description : In the power amplifier shown in figure 2-10, what two signals are mixed to produce the output signal?
Last Answer : Local oscillator and coherent oscillator.
Description : What is the primary difference between the pump signal of a simple parametric amplifier and the pump signal of a nondegenerative parametric amplifier?
Last Answer : The pump signal of a nondegenerative parametric amplifier is higher than twice the input signal.
Description : What type of amplifier would be used to amplify the signal from a radio antenna?
Last Answer : An rf voltage amplifier.
Description : If the operating point of an NPN transistor amplifier is selected in saturation region, it is likely to result in A) Thermal runaway of transistor B) Clipping of output in the positive half of the ... for high dc collector supply D) Clipping of output in the negative half of the input signal
Last Answer : B) Clipping of output in the positive half of the input signal
Description : Which of the following is not true: A) An oscillator is a circuit that converts DC to AC B) An oscillator is an amplifier that supplies its own input signal C) All oscillators generate sine waves D) In phase feedback is called positive Feedback
Last Answer : C) All oscillators generate sine waves
Description : The circuit which changes input signal at output with phase shift of 1800 is called (a) Amplifier (b) operational amplifier (c) switch (d) inverter
Last Answer : (d) inverter
Description : Negative feedback amplifier has a signal corrupted by noise as its input. The amplifier will (A) Amplify the noise as much as the signal (B) Reduce the noise (C) Increase the noise (D) Not effect the noise
Last Answer : Negative feedback amplifier has a signal corrupted by noise as its input. The amplifier will Reduce the noise
Description : Which components provide the regenerative feedback signal in the phase-shift oscillator?
Last Answer : Resistor-capacitor networks.
Description : How can a series-positive limiter be modified to limit unwanted negative portions of the input signal?
Last Answer : Biasing.
Description : . When you select the time base to display a signal, should the time base be the same, higher, or lower than the input signal?
Last Answer : Lower.
Description : In applications where electronic waveforms are displayed on a CRT screen, the input signal is normally applied to what CRT element?
Last Answer : The vertical-deflection plate.
Description : In a circuit such as that shown in figure 3-16, if R1 has a value of 50 ohms and R2 has a value of 250 ohms and the input signal has a value of +10 millivolts, what is the value of the output signal?
Last Answer : 60 millivolts.
Description : In a circuit such as that shown in figure 3-15, if R1 has a value of 100 ohms and R2 has a value of 1 kilohm and the input signal is at a value of + 5 millivolts, what is the value of the output signal?
Last Answer : 50 millivolts.
Description : In the inverting configuration when the noninverting input is grounded, the inverting input is at (signal, virtual) ground
Last Answer : Virtual.
Description : In the inverting configuration, the input signal is applied to the (a) (inverting, noninverting) input and the feedback signal is applied to the (b) (inverting, noninverting) input.
Last Answer : a. Inverting. b. Inverting.
Description : select the correct response from the choices given in the parentheses. Q-20. In a closed-loop configuration the output signal is determined by (the input signal, the feedback signal, both).
Last Answer : Both the input signal and the feedback signal.
Description : If If the input signals are 180 degrees out of phase with each other and a combined output is taken between the two output terminals, what will the amplitude of the combined output signal be?
Last Answer : 200 millivolts.
Description : Does a rectifier tube conduct on the positive or negative alternation of the input signal?
Last Answer : Positive.
Description : What type of feedback aids an input signal?
Last Answer : Regenerative or positive
Description : When measuring harmonic distortion, you set the signal generator to input a 15-kHz test signal. To what frequency should you set the wave analyzer?
Last Answer : 45 kHz.
Description : Two tape recorders have signal-to-noise ratios (SNRs) of 25-dB RMS and 35-dB RMS respectively. Which of the SNRs can record and reproduce the widest range of input signals and why?
Last Answer : 35-dB RMS because the highest SNR can always record and reproduce the widest range of input signals.
Description : What are three advantages of adding an ac bias voltage to the input signal instead of adding a fixed dc bias voltage?
Last Answer : a. Reproduces a stronger output signal. b. Greatly improves the SNR. c. Greatly reduces the natural tape hiss.
Description : Why does adding dc vice ac bias voltage to the input signal result in a poor signal-to-noise ratio (SNR)?
Last Answer : With dc bias, the SNR is poor because only a small portion of the magnetism curve is straight enough to use, thus the output signal is weak compared with the natural tape hiss.
Description : How does dc bias added to the input signal correct the distortion in the output signal?
Last Answer : The dc bias moves the input signal away from the step in the magnetism curve. This prevents the input signal from crossing the zero-point of the magnetism curve.