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 : 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 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 : 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 : Common basic applications for the operational amplifier include ____________. A. counting, pulsing and clocking amplifiers B. summing, scaling and difference amplifiers C. step-up, step-down and rectifying amplifiers D. all of the above
Last Answer : Answer: B
Description : What is the polarity of the first alternation of the tank circuit in an emitter-loaded npn pulsed oscillator?
Last Answer : Negative
Description : What is average power in a pulsed system?
Last Answer : Peak power during a pulse averaged over pulse time plus rest time.
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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : Why won't my eye stop pulsing?
Last Answer : Are you lacking sleep lately? Tired? That can also be a reason.
Description : The acceleration of flowering by manipulating environmental conditions is known as: a. Pulsing b. Forcing c. Leaching d. After-ripening
Last Answer : Forcing
Description : In a ____________ advertising schedule, advertising is used during every period of the campaign, but the amount of advertising varies considerably from period to period. 1. flighting 2. dated 3. plotted 4. pulsing 5. continuous
Last Answer : pulsing
Description : Which is the proper measurement of average power emitted by a pulsed laser? a. Energy x time b. Pulse energy x repetition rate c. Pulse energy / repetition rate d. Peak power x pulse length
Last Answer : b. Pulse energy x repetition rate
Description : Used for time division multiplexing. A. Frequency modulation B. Pulsed modulation C. SSB D. Amplitude modulation
Last Answer : B. Pulsed modulation
Description : The sinusoidal carrier is pulsed so that one of the binary states is represented by a carrier while the other is represented by its absence. A. FSK B. ASK C. PSK D. QAM
Last Answer : B. ASK
Description : Which of the following is the most suitable for extraction in a system having very low density difference? (A) Mixer-settler extractor (B) Centrifugal extractor (C) Pulsed extractor (D) Packed extraction tower
Last Answer : (B) Centrifugal extractor
Description : Radioactive nuclear waste is treated in (A) Mixer-settler extractor (B) Rotating-disc contactor (C) Pulsed column extractor (D) Bollman extractor
Last Answer : (C) Pulsed column extractor
Description : __________ extractor is used for the concentration of radioactive nuclear waste. (A) Pulsed column (B) Sieve plate (C) Mixer-settler (D) Bollman
Last Answer : (A) Pulsed column
Description : Which of the following methods refers to deactivation of microbes in food using electricity? A. Power Ultrasound B. Pulsed Electric field C. Hurdle technology D. All of the above
Last Answer : B. Pulsed Electric field
Description : How does a touch tone receiver differs from pulsed dial receiver? Explain with schematic.
Last Answer : Pulse dialing: 1. Generated through make and break contact. 2. DC Current pulse is generated. 3. Each number is separated by a short pause to prevent overlapping. 4. Codes ... dialing pulse is not misinterpreted as the phone being returned to its on-hook (idle) condition.
Description : Which is the proper measurement of average power emitted by a pulsed laser? ∙ a. Energy x time ∙ b. Pulse energy x repetition rate ∙ c. Pulse energy / repetition rate ∙ d. Peak power x pulse length
Last Answer : ∙ b. Pulse energy x repetition rate
Description : Describe the operation for pulsed radar to detect the object.
Last Answer : The Block diagram of high power Pulsed RADAR set is shown in fig. Above. Trigger Source: It Provides pulses for the modulator. Pulse Modulator: This Modulator provides rectangular ... . Sync pulses are applied by the trigger source to the display devices or the display indicator.
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 : 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.