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 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 : What is the result of pulsing a pulsed rf amplifier when no rf is present?
Last Answer : Oscillations at an undesired frequency.
Description : If the rf amplifier discussed has an 80 milliwatt input, what would be the maximum output?
Last Answer : 800 watts.
Description : For what class of operation is the final rf power amplifier of a plate-modulator circuit biased?
Last Answer : Class C
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 : Which of the following methods cannot be used to increase the bandwidth for cascaded RF amplifier stages? A) Wave traps in each stage B) Stagger tuning C) A shunt damping resistor across each tuned circuit D) Doubled tuned transformers with tighter coupling
Last Answer : A) Wave traps in each stage
Description : One of the following is a possible cause of an abrupt frequency variation in a self exited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency ... capacitor in the oscillator D. Loose connections in the oscillator, amplifier, or antenna circuits.
Last Answer : D. Loose connections in the oscillator, amplifier, or antenna circuits.
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 : If the unity-gain point of the operational amplifier used in question 24 is 500 kilohertz, what is the bandwidth of the circuit?
Last Answer : 50 kilohertz (Gain = 10; Gain-Bandwidth Product = 500,000) 500,000(Hz)
Description : What happens to the overall gain of a lin-log amplifier as each stage saturates?
Last Answer : Decreases.
Description : What are four methods of coupling amplifier stages?
Last Answer : Direct, RC, impedance, and transformer coupling.
Description : One of the following is a high powered RF ac basic transmitter that has two or more stages, the oscillator stage which determines the frequency opereation and RF amplifier stage orstages that develop the ... to develop a good frequency stability. A. Goldsmith B. MOPA C. Alexanderson D. Hartley
Last Answer : B. MOPA
Description : When measuring a transmitter’s frequency against a suitable standard, the frequency to be measured is taken from the A. oscillator stage B. intermediate amplifier C. buffer stage D. final RF stage
Last Answer : D. final RF stage
Description : What is the meaning of forward power? A. The power traveling from the transmitter to the antenna. B. The power radiated from the top of an antenna system. C. The power produced during the positive half of an RF cycle. D. The power used to drive a linear amplifier.
Last Answer : A. The power traveling from the transmitter to the antenna.
Description : What establishes the receiver bandwidth? A. RF amplifier B. Mixer C. Local oscillator D. IF amplifier
Last Answer : D. IF amplifier
Description : What consists the front-end circuit of a VHF TV superheterodyne receiver? A. Mixer, RF amplifier and AFC? B. RF amplifier, Band pass filter and mixer C. Local oscillator, mixer and RF amplifier D. Local oscillator, AGC and antenna
Last Answer : C. Local oscillator, mixer and RF amplifier
Description : Which of the following parts of the radio receiver represent the component that extracts the desire RF signal from the electromagnetic wave? A. AF amplifier B. Antenna C. Detector D. Crystal
Last Answer : B. Antenna
Description : Refers to one of the front end circuit of a VHF TV superheterodyne receiver which is usually a separate circuit coupled to the mixer. A. Antenna feed B. AGC C. RF amplifier D. Local oscillator
Last Answer : D. Local oscillator
Description : Which of the following is one of the possible causes for a slow drift of frequency in a self exited transmitter oscillator circuits resulting to a poor frequency stability? A. Poor soldered connections ... , or antenna circuits D. DC and RF heating of resistors, causing then to change values.
Last Answer : D. DC and RF heating of resistors, causing then to change values.
Description : After the IF stages have been aligned, the next stage to align in FM receiver is. A. local oscillator B. limiter stage C. RF amplifier D. mixer stage
Last Answer : A. local oscillator
Description : In a Klystron amplifier, the RF voltage produces (a) amplitude modulation (b) frequency modulation (c) phase modulation (d) velocity modulation
Last Answer : In a Klystron amplifier, the RF voltage produces velocity modulation
Description : How do you compensate for the resistance of the test leads of a meter?
Last Answer : . By zeroing the meter with the test leads shorted.
Description : The Doppler effect causes a change in what aspect of rf energy that strikes a moving object?
Last Answer : Frequency.
Description : Rotation of an rf-feed source to produce a conical scan pattern is identified by what term?
Last Answer : Nutation.
Description : Atmospheric interference with the travel of electromagnetic energy increases with what rf energy characteristic?
Description : At what point on an open-circuited rf line do voltage peaks occur?
Last Answer : At 1/2 wavelength from the end and at every 1/2 wavelength along the line
Description : What is the most common method of testing a fixed rf attenuator?
Last Answer : Rf substitution method.
Description : Normally, how are high-power rf tubes tested?
Last Answer : In their circuit.
Description : Name the three main sections of a typical rf signal generator.
Last Answer : Oscillator circuit, modulator, and output control circuit.
Description : If a wave's electric lines of force rotate through 360 degrees with every cycle of rf energy, what is the polarization of this wave?
Last Answer : Circular polarization.
Description : How does the reactance-tube modulator impress intelligence onto an rf carrier?
Last Answer : By changing the reactance of an oscillator circuit in consonance with the modulating voltage.
Description : The product of the radiated RF power of a transmitter and the gain of the antenna system in a given direction relative to an isotropic radiator is called ____. A. Effective Radiated Power (ERP) B. Effective Isotropic Radiated Power (EIRP) C. Radiated Power D. Transmit Power
Last Answer : B. Effective Isotropic Radiated Power (EIRP)
Description : How can receiver desensitizing be reduced? A. Increase the receiver bandwidth B. Ensure good RF shielding between the transmitter and receiver C. Increase the transmitter audio gain D. Decrease the receiver squelch, gain.
Last Answer : D. Decrease the receiver squelch, gain.
Description : What component in an amplifier circuit tends to limit the low-frequency response of the amplifier?
Last Answer : The coupling capacitor (C3).
Description : The operational amplifier is _______ (a) High gain amplifier (b) high power amplifier (c)high resistance amplifier (d)low resistance amplifier
Last Answer : a) High gain amplifier
Description : The main component responsible for the fall of gain of an RC coupled amplifier in low frequency range is (A) The active device itself (tube, or transistor) (B) stray shunt capacitance Cs (C) the grid leak resistance Rg (D) coupling capacitor Cc
Last Answer : The main component responsible for the fall of gain of an RC coupled amplifier in low frequency range is coupling capacitor Cc
Description : The nurse recognizes which of the following signs as typical of the patient in shock? a) Rapid, weak, thready pulse Pulse increases as the body tries to compensate. b) Flushed face Pallor is ... urine output Usually, a low blood pressure and concentrated urine are observed in the patient in shock.
Last Answer : a) Rapid, weak, thready pulse Pulse increases as the body tries to compensate.
Description : Which digital data encoding method helps overcome a tape recorder’s low-frequency response problems by recording two logic levels for each incoming data bit?
Last Answer : Bi-phase level encoding.
Description : What two primary items determine the class of operation of an amplifier?
Last Answer : The amount of bias and the amplitude of the input signal
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").