E7B01

For what portion of a signal cycle does a Class AB amplifier operate?

1. More than 180 degrees but less than 360 degrees

E7B02

Which class of amplifier, of the types shown, provides the highest efficiency?

1. Class C

E7B03

Where on the load line of a Class A common emitter amplifier would bias normally be set?

1. Approximately half-way between saturation and cutoff

E7B04

What can be done to prevent unwanted oscillations in a power amplifier?

1. Install parasitic suppressors and/or neutralize the stage

E7B05

Which of the following amplifier types reduces or eliminates even-order harmonics?

1. Push-pull

E7B06

Which of the following is a likely result when a Class C rather than a class AB amplifier is used to amplify a single-sideband phone signal?

1. The signal may become distorted and occupy excessive bandwidth

E7B07

How can a vacuum-tube power amplifier be neutralized?

1. By feeding back an out-of-phase component of the output to the input

E7B08

Which of the following describes how the loading and tuning capacitors are to be adjusted when tuning a vacuum tube RF power amplifier that employs a pi-network output circuit?

1. The tuning capacitor is adjusted for minimum plate current, while the loading capacitor is adjusted for maximum permissible plate current

E7B09

In Figure E7-1, what is the purpose of R1 and R2?

1. Fixed bias

E7B10

In Figure E7-1, what is the purpose of R3?

1. Self bias

E7B11

What type of circuit is shown in Figure E7-1?

1. Common emitter amplifier

E7B12

In Figure E7-2, what is the purpose of R?

1. Emitter load

E7B13

In Figure E7-2, what is the purpose of C2?

1. Output coupling

E7B14

What is one way to prevent thermal runaway in a transistor amplifier?

1. Use degenerative emitter feedback

E7B15

What is the effect of intermodulation products in a linear power amplifier?

1. Transmission of spurious signals

E7B16

Why are third-order intermodulation distortion products of particular concern in linear power amplifiers?

1. Because they are relatively close in frequency to the desired signal

E7B17

Which of the following is a characteristic of a grounded-grid amplifier?

1. Low input impedance

E7B18

What is a klystron?

1. A VHF, UHF, or microwave vacuum tube that uses velocity modulation

E7B19

What is a parametric amplifier?

1. A low-noise VHF or UHF amplifier relying on varying reactance for amplification

E7B20

Which of the following devices is generally best suited for UHF or microwave power amplifier applications?

1. FET

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