Q.1

In a class B push-pull amplifier, the transistors are biased slightly above cutoff to avoid

  • crossover distortion
  • unusually high efficiency
  • negative feedback
  • a low input impedance
Q.2

Often a common-collector will be the last stage before the load; the main function of this stage is to

  • provide voltage gain
  • buffer the voltage amplifiers from the low-resistance load
  • provide phase inversion
  • provide a high-frequency path to improve the frequency response
Q.3

The primary function of the bias circuit is to

  • hold the circuit stable at VCC
  • hold the circuit stable at vin
  • ensure proper gain is achieved
  • hold the circuit stable at the designed Q-point
Q.4

The depletion-mode MOSFET

  • can operate with only positive gate voltages
  • can operate with only negative gate voltages
  • cannot operate in the ohmic region
  • can operate with positive as well as negative gate voltages
Q.5

In order for feedback oscillators to have any practical value, the gain has to be

  • < 1
  • self-adjusting
  • stabilized
  • nonlinear
Q.6

To get a negative gate-source voltage in a self-biased JFET circuit, you must use a

  • voltage divider
  • source resistor
  • ground
  • negative gate supply voltage
Q.7

A JFET

  • is a current-controlled device
  • has a low input resistance
  • is a voltage-controlled device
  • is always forward-biased
Q.8

Three different points are shown on a dc load line. The upper point represents the

  • minimum current gain
  • quiescent point
  • saturation point
  • cutoff point
Q.9

Which of the following conditions are needed to properly bias an npn transistor amplifier?

  • Forward bias the base/emitter junction and reverse bias the base/collector junction.
  • Forward bias the collector/base junction and reverse bias the emitter/base junction.
  • Apply a positive voltage on the n-type material and a negative voltage on the p-type material.
  • Apply a large voltage on the base.
Q.10

The capacitor that produces an ac ground is called a(n)

  • coupling capacitor
  • dc open
  • bypass capacitor
  • ac open
Q.11

Which of the following conditions are needed to properly bias an npn transistor amplifier?

  • Forward bias the base/emitter junction and reverse bias the base/collector junction.
  • Forward bias the collector/base junction and reverse bias the emitter/base junction.
  • Apply a positive voltage on the n-type material and a negative voltage on the p-type material.
  • Apply a large voltage on the base.
Q.12

The formula used to calculate the approximate ac resistance of the base-emitter diode (re) is

  • mca17_1005a1.gif
  • re almostequal.jpg 25 mV × IC
  • mca17_1005c1.gif
  • mca17_1005d1.gif
Q.13

The formula used to calculate the approximate ac resistance of the base-emitter diode (re) is

  • mca17_1005a1.gif
  • re almostequal.jpg 25 mV × IC
  • mca17_1005c1.gif
  • mca17_1005d1.gif
Q.14

A certain amplifier has a voltage gain ofThat gain expressed in decibels is 46.4 dB.

  • True
  • False
Q.15

The voltage measured from the collector to the emitter is the sum of the voltage base-emitter plus the voltage collector-base.

  • True
  • False
Q.16

A decrease in base current of a CE amplifier causes the voltage measured between the emitter and the collector to increase.

  • True
  • False
Q.17

In an n-type JFET, current will flow when a positive voltage is applied to the drain and a negative voltage is applied to the source.

  • True
  • False
Q.18

If the drain, source, and channel of a MOSFET are all a p-type material, and it operates in both modes, this is an n-channel D-MOSFET.

  • True
  • False
Q.19

A practical CE amplifier has the input on the base and the output taken off the emitter.

  • True
  • False
Q.20

An essential requirement of a feedback oscillator is a phase shift around the feedback loop of 360°.

  • True
  • False
0 h : 0 m : 1 s