IndiaBix - Bipolar Junction Transistors (BJT)

a

For a C-C configuration to operate properly, the collector-base junction should be reverse biased, while forward bias should be applied to which junction? A. collector-emitter B. base-emitter C. collector-base D. cathode-anode

b

If VCC = +18 V, voltage-divider resistor R1 is 4.7 kΩ, and R2 is 1500 Ω, what is the base bias voltage? A. 8.70 V B. 4.35 V C. 2.90 V D. 0.7 V

d

If a 2 mV signal produces a 2 V output, what is the voltage gain? A. 0.001 B. 0.004 C. 100 D. 1000

d

If a transistor operates at the middle of the dc load line, a decrease in the current gain will move the Q point: A. off the load line B. nowhere C. up D. down

c

If an input signal ranges from 20-40 µA (microamps), with an output signal ranging from .5-1.5 mA (milliamps), what is the ac beta? A. 0.05 B. 20 C. 50 D. 500

a

In a C-E configuration, an emitter resistor is used for: A. stabilization B. ac signal bypass C. collector bias D. higher gain

b

In a transistor, collector current is controlled by: A. collector voltage B. base current C. collector resistance D. all of the above

b

Most of the electrons in the base of an NPN transistor flow: A. out of the base lead B. into the collector C. into the emitter D. into the base supply

d

Often a common-collector will be the last stage before the load; the main function(s) of this stage is to: A. provide voltage gain B. provide phase inversion C. provide a high-frequency path to improve the frequency response D. buffer the voltage amplifiers from the low-resistance load and provide impedance matching for maximum power transfer

a

The ends of a load line drawn on a family of curves determine: A. saturation and cutoff B. the operating point C. the power curve D. the amplification factor

d

The input/output relationship of the common-collector and common-base amplifiers is: A. 270 degrees B. 180 degrees C. 90 degrees D. 0 degrees

b

Voltage-divider bias provides: A. an unstable Q point B. a stable Q point C. a Q point that easily varies with changes in the transistor's current gain D. a Q point that is stable and easily varies with changes in the transistor's current gain

c

What is the collector current for a C-E configuration with a beta of 100 and a base current of 30 µA? A. 30 µA B. .3 µA C. 3 mA D. 3 MA

d

What is the current gain for a common-base configuration where IE = 4.2 mA and IC = 4.0 mA? A. 16.80 B. 1.05 C. 0.20 D. 0.95

c

When a silicon diode is forward biased, what is VBE for a C-E configuration? A. voltage-divider bias B. 0.4 V C. 0.7 V D. emitter voltage

c

The Q point on a load line may be used to determine: A. VC B. VCC C. VB D. IC

b

A collector characteristic curve is a graph showing: A. emitter current (IE) versus collector-emitter voltage (VCE) with (VBB) base bias voltage held constant B. collector current (IC) versus collector-emitter voltage (VCE) with (VBB) base bias voltage held constant C. collector current (IC) versus collector-emitter voltage (VC) with (VBB) base bias voltage held constant D. collector current (IC) versus collector-emitter voltage (VCC) with (VBB) base bias voltage held constant

c

A current ratio of IC/IE is usually less than one and is called: A. beta B. theta C. alpha D. omega

b

A transistor has a of 250 and a base current, IB, of 20 µA. The collector current, IC, equals: A. 500 µA B. 5 mA C. 50 mA D. 5 A

d

A transistor may be used as a switching device or as a: A. fixed resistor B. tuning device C. rectifier D. variable resistor

a

The C-B configuration is used to provide which type of gain? A. voltage B. current C. resistance D. power

a

The symbol hfe is the same as: A. βDC B. αDC C. hi-fi D. βAC

c

Three different Q points are shown on a dc load line. The upper Q point represents the: A. minimum current gain B. intermediate current gain C. maximum current gain D. cutoff point

d

To operate properly, a transistor's base-emitter junction must be forward biased with reverse bias applied to which junction? A. collector-emitter B. base-collector C. base-emitter D. collector-base

c

Total emitter current is: A. IE - IC B. IC + IE C. IB + IC D. IB - IC

c

When transistors are used in digital circuits they usually operate in the: A. active region B. breakdown region C. saturation and cutoff regions D.linear region

a

Which is beta's current ratio? A. IC/IB B. IC/IE C. IB/IE D. IE/IB

d

Which is the higher gain provided by a C-E configuration? A. voltage B. current C. resistance D. power

a

With a PNP circuit, the most positive voltage is probably: A. ground B. VC C. VBE D. VCC

b

With low-power transistor packages, the base terminal is usually the: A. tab end B. middle C. right end D. stud mount

c

With the positive probe on an NPN base, an ohmmeter reading between the other transistor terminals should be: A. open B. infinite C. low resistance D. high resistance