# Bipolar Junction Transistors (Bjt) MCQs

## 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

• A. beta
• B. theta
• C. alpha
• D. omega

## A transistor may be used as a switching device or as a:

• A. fixed resistor
• B. tuning device
• C. rectifier
• D. variable resistor

## An emitter-follower has a voltage gain that is __________.

• A. much less than one
• B. approximately equal to one
• C. greater than one
• D. zero

## Base bias provides _________.

• A. a very stable Q point
• B. a very unstable Q point
• C. no current gain
• D. zero current in the base and collector circuits

## 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

• A. 0.001
• B. 0.004
• C. 100
• D. 1000

## 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

• A. 0.05
• B. 20
• C. 50
• D. 500

• A. 8.70 V
• B. 4.35 V
• C. 2.90 V
• D. 0.7 V

## In a C-E configuration, an emitter resistor is used for:

• A. stabilization
• B. ac signal bypass
• C. collector bias
• D. higher gain

## In a transistor, collector current is controlled by:

• A. collector voltage
• B. base current
• C. collector resistance
• D. all of the above

## 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

## 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

## The C-B configuration is used to provide which type of gain?

• A. voltage
• B. current
• C. resistance
• D. power

## 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

## The input resistance of the base of an emitter-follower is usually _________.

• A. very low
• B. very high
• C. shorted to ground
• D. open

## 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

• A.
• B. 90º
• C. 180º
• D. 360º

• A. VC
• B. VCC
• C. VB
• D. IC

## 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

## 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

• A. IE – IC
• B. IC + IE
• C. IB + IC
• D. IB – IC

• A. VCC
• B. VB
• C. 0.2 V
• D. 0.7 V

• A. VC
• B. VB
• C. 0.3 V
• D. 0.7 V

## 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

• A. 30 A
• B. .3 A
• C. 3 mA
• D. 3 MA

• A. 16.80
• B. 1.05
• C. 0.20
• D. 0.95

## 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

## 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. IC/IB
• B. IC/IE
• C. IB/IE
• D. IE/IB

## Which is the higher gain provided by a C-E configuration?

• A. voltage
• B. current
• C. resistance
• D. power

• A. ground
• B. VC
• C. VBE
• D. VCC

## With low-power transistor packages, the base terminal is usually the:

• A. tab end
• B. middle
• C. right end
• D. stud mount