BIPOLAR JUNCTION TRANSISTORS Flashcards
A transistor amplifier has a voltage
gain of 100. If the input voltage is 75 mV,
the output voltage is:
7.5V
What is the ratio of IC to IB?
either βDC or hFE, but not αDC
For normal operation of a pnp BJT, the
base must be ________ with respect to
the emitter and ________ with respect
to the collector.
negative, positive
When a transistor is used as a switch,
it is stable in which two distinct regions?
saturation and cut off
The term BJT is short for
bipolar junction transistor
For a silicon transistor, when a base-
emitter junction is forward-biased, it has
a nominal voltage drop of
0.7V
A certain transistor has IC = 15 mA
and IB = 167µA; βDC is:
90
What does βDC vary with?
both IC and ºC
A BJT has an IB of 50µA and a βDC of
75; IC is:
3.75 mA
What are the two types of bipolar
junction transistors?
npn and pnp
The value of βDC
varies with temperature and
IC.
A transistor data sheet usually
identifies βDC as
hFE.
What is the ratio of IC to IE?
either βDC / (βDC + 1) or αDC, but
not βDC
Which of the following is true
for an npn or pnp transistor?
IE = IB + IC
What is the order of doping, from
heavily to lightly doped, for each region?
emitter, collector, base
In what range of voltages is the
transistor in the linear region of its
operation?
0.7 < VCE < VCE(max)
The magnitude of dark current in a
phototransistor usually falls in what
range?
nA
A 35 mV signal is applied to the base
of a properly biased transistor with an r’e
= 8 and RC = 1 k. The output signal
voltage at the collector is:
4.375 V
What is (are) general-purpose/small-
signal transistors case type(s)?
TO-18
TO-92
TO-39
TO-52
What is (are) common fault(s) in a
BJT-based circuit?
opens or shorts internal to the
transistor
open bias resistor(s)
external opens and shorts on
the circuit board
The dc load line on a family of
collector characteristic curves of a
transistor shows the
saturation region.
cutoff region.
active region.
