Description : What amplifier class of operation is the most inefficient but has the least distortion?
Last Answer : Class A.
Description : For what class of operation is the final rf power amplifier of a plate-modulator circuit biased?
Last Answer : Class C
Description : What determines the class of operation of an amplifier?
Last Answer : The amount of time (in relation to the input signal) in which current flows in the output circuit.
Description : The underlying principle of operation of the parametric amplifier is based on what property?
Last Answer : Reactance.
Description : What are the four classes of operation of a transistor amplifier?
Last Answer : A, AB, B, C.
Description : What is the primary advantage of power-amplifier transmitters over keyed-oscillator transmitters?
Last Answer : Frequency stability.
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 : Explain with circuit diagram and waveform the operation of class AB push pull power amplifier.
Last Answer : Class AB Push Pull Power Amplifier: Circuit Diagram: Circuit Decription: The circuit consists of two centre-tapped transformers T1 and T2, two identical transistors Q1 and Q2 , Resistor R and ... two halves & produces a full sine wave in the load resistor. Waveform :
Description : Describe the operation of class-C type of power amplifier with the help of neat sketch.
Last Answer : Circuit diagram: Operation: * Class C power amplifier is a type of amplifier where the transistor conducts for less than one half cycle of the input signal. Less than one ... resonant circuit oscillates in one frequency (generally the carrier frequency) all other frequencies are attenuated.
Description : Draw diagram of class A push-pull amplifier and explain its operation.
Last Answer : Class A Push-pull Amplifier: The circuit diagram of class A push-pull amplifier is as shown in the fig.(a). Operation: The resistors R1 and R2 along with Vcc provide the dc biasing so as ... Vcc is applied to the collectors of transistors Q1 and Q2 through the centretapped output transformer.
Description : Determine the lower half-power frequency of a class-C amplifier having upper half-power frequency of 10.025 MHz, a resonant frequency 5 MHz and a circuit Q of 10. A. 1.0025 MHz B. 10.525 MHz C. 0.5 MHz D. 10 MHz
Last Answer : A. 1.0025 MHz
Description : What two variables determine the primary frequency of a resonant cavity?
Last Answer : Size and shape of the cavity.
Description : What class of operation has the highest fidelity?
Last Answer : Class A operation.
Description : Why is class C operation more efficient than class A operation?
Last Answer : The amplifier operates (and therefore uses power) for less time in class C than in class A.
Description : If the output of a circuit needs to be a complete representation of one-half of the input signal, what class of operation is indicated?
Last Answer : Class B operation.
Description : What two methods are used to compensate for the problems that cause low gain in an rf amplifier?
Last Answer : . RF transformers are used and the transistor is neutralized.
Description : Can a difference amplifier have more than two inputs?
Last Answer : No
Description : Can a summing amplifier have more than two inputs?
Last Answer : Yes, a summing amplifier can have as many inputs as desired.
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 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 : 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 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 : If C4 were removed from the circuit, what would happen to the output of the amplifier?
Last Answer : The output would decrease. (C4 decouples R2 preventing degenerative feedback from R2.)
Description : What components form the input-signal-developing impedance for the amplifier?
Last Answer : C2 and the secondary of T1.
Description : What problem is caused in an rf amplifier by a loosely coupled transformer?
Last Answer : A too-narrow bandpass.
Description : What is the most common form of coupling for an rf amplifier?
Last Answer : Transformer coupling.
Description : Can a parallel LC circuit be used as the frequency determining network for an rf amplifier?
Last Answer : Yes.
Description : What is the purpose of a frequency-determining network in an rf amplifier?
Last Answer : To provide maximum impedance at the desired frequency.
Description : If the output impedance of an amplifier circuit is decreased, what is the effect on the gain?
Last Answer : The gain decreases.
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 : What component in an amplifier circuit tends to limit the low-frequency response of the amplifier?
Last Answer : The coupling capacitor (C3).
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 is the major factor that limits the high-frequency response of an amplifier circuits?
Last Answer : The capacitance of the circuit.
Description : What are the factors that limit the frequency response of a transistor amplifier?
Last Answer : The capacitance and inductance of the circuit and the interelectrode capacitance of the transistor.
Description : If current gain is required from an rf amplifier, what type of component should be used as an output coupling element?
Last Answer : A step-down transformer.
Description : What are the upper and lower frequency limits of an amplifier?
Last Answer : The half-power points of a frequency-response curve. The upper and lower limits of the band f frequencies for which the amplifier is most effective.
Description : What is the bandwidth of an amplifier?
Last Answer : The difference between the upper and lower frequency limits of an amplifier.
Description : When is degeneration tolerable in an amplifier?
Last Answer : When it is necessary to prevent amplitude distortion.
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 : What is the purpose of the rectifier in a magnetic amplifier?
Last Answer : The rectifier eliminates hysteresis loss.
Description : At what portion of the magnetization curve should a magnetic amplifier be operated?
Last Answer : . The knee of the curve.
Description : What is the basic principle of a magnetic amplifier?
Last Answer : change in inductance in a series LR circuit causes a change in true power.
Description : What is the frequency classification of a magnetic amplifier
Last Answer : An audio (or low) frequency power amplifier.
Description : What is the difference between a subtractor and a difference amplifier?
Last Answer : . The difference amplifier multiplies the difference between the two inputs by the gain of the circuit while the subtractor merely subtracts one input signal from the other
Description : What is a scaling amplifier?
Last Answer : A summing amplifier that applies a factor to each input signal beforeadding the results.