Boylestad: MCQ in Bipolar Junction Transistors

B

In what decade was the first transistor created?

A) 1930s

B) 1940s

C) 1950s

D) 1960s

C

How many layers of material does a transistor have?

A) 1

B) 2

C) 3

D) 4

D

What is the ratio of the total width to that of the center layer for a transistor?

A) 1:15

B) 1:150

C) 15:1

D) 150:1

D

Which of the following is (are) the terminal(s) of a transistor?

A) Emitter

B) Base

C) Collector

D) All of the above

B

List the types of bipolar junction transistors.

A) ppn, npn

B) pnp, npn

C) npp, ppn

D) nnp, pnp

B

Transistors are _______-terminal devices.

A) 2

B) 3

C) 4

D) 5

A

How many carriers participate in the injection process of a unipolar device?

A) 1

B) 2

C) 0

D) 3

C

Which component of the collector current IC is called the leakage current?

A) Majority

B) Independent

C) Minority

D) None of the above

C

For a properly biased pnp transistor, let IC = 10 mA and IE = 10.2 mA. What is the level of IB?

A) 0.2 A

B) 200 mA

C) 200 µA

D) 20.2 mA

A

Calculate minority current ICO if IC = 20.002 mA and IC majority = 20 mA.

A) 2 µA

B) 0.002 µA

C) 2 nA

D) 2 pA

D

Which of the following regions is (are) part of the output characteristics of a transistor?

A) Active

B) Cutoff

C) Saturation

D) All of the above

C

In which region are both the collector-base and base-emitter junctions forward-biased?

A) Active

B) Cutoff

C) Saturation

D) All of the above

B

How much is the base-to-emitter voltage of a transistor in the "on" state?

A) 0 V

B) 0.7 V

C) 0.7 mV

D) Undefined

C

In the active region, while the collector-base junction is ______-biased, the base-emitter is ______-biased.

A) forward, forward

B) forward, reverse

C) reverse, forward

D) reverse, reverse

C

What is βdc equal to?

A) IB / IE

B) IC / IE

C) IC / IB

D) None of the above

D

For what kind of amplifications can the active region of the common-emitter configuration be used?

A) Voltage

B) Current

C) Power

D) All of the above

A

Use this table of collector characteristics to calculate βac at VCE = 15 V and IB = 30 µA.

A) 100

B) 106

C) 50

D) 400

D

Calculate βdc at VCE = 15 V and IB = 30 µA.

A) 100

B) 116

C) 50

D) 110

D

Which of the following configurations can a transistor set up?

A) Common-base

B) Common-emitter

C) Common-collector

D) All of the above

C

Determine the value of α when β = 100.

A) 1.01

B) 101

C) 0.99

D) Cannot be solved with the information provided

C

What is the most frequently encountered transistor configuration?

A) Common-base

B) Common-collector

C) Common-emitter

D) Emitter-collector

D

βdc for this set of collector characteristics is within _____ percent of βac.

A) 2

B) 5

C) 7

D) 10

D

What is (are) the component(s) of most specification sheets provided by the manufacturer?

A) Maximum ratings

B) Thermal characteristics

C) Electrical characteristics

D) All of the above

D

Most specification sheets are broken down into _______.

A) maximum ratings

B) thermal characteristics

C) electrical characteristics

D) All of the above

B

An example of a pnp silicon transistor is a 2N4123.

A) True

B) False

D

Which of the following equipment can check the condition of a transistor?

A) Current tracer

B) Digital display meter (DDM)

C) Ohmmeter (VOM)

D) All of the above

D

Which of the following can be obtained from the last scale factor of a curve tracer?

A) hFE

B) αdc

C) αac

D) βac

A

Calculate βac for IC = 15 mA and VCE = 5 V.

A) 200

B) 180

C) 220

D) None of the above

A

What range of resistor values would you get when checking a transistor for forward- and reverse-biased conditions by an ohmmeter?

A) 100 Ω to a few kΩ, exceeding 100 kΩ

B) Exceeding 100 kΩ, 100 Ω to a few kΩ

C) Exceeding 100 kΩ, exceeding 100 kΩ

D) 100 Ω to a few kΩ, 100 Ω to a few kΩ

A

What does a reading of a large or small resistance in forward- and reverse-biased conditions indicate when checking a transistor using an ohmmeter?

A) Faulty device

B) Good device

C) Bad ohmmeter

D) None of the above

A

How many individual pnp silicon transistors can be housed in a 14-pin plastic dual-in-line package?

A) 4

B) 7

C) 10

D) 14

B

All amplifiers should have at least _____ terminals with _____ terminal(s) controlling the flow between _____ other terminal(s).

A) 2, 1, 1

B) 3, 1, 2

C) 3, 2, 1

D) 3, 0, 3

C

The outer layers of a transistor are _______ the sandwiched layer.

A) much smaller than

B) the same as

C) much larger than

D) None of the above

A

The doping of the sandwiched layer is _______ that of the outer layers.

A) considerably less than

B) the same as

C) considerably more than

D) None of the above

D

The lower doping level _______ the conductivity and _______ the resistivity of the material.

A) increases, decreases

B) increases, increases

C) decreases, decreases

D) decreases, increases

B

The term bipolar reflects the fact that _______ and _______ participate in the injection process into the oppositely polarized material.

A) holes, neutrons

B) holes, electrons

C) neutrons, electrons

D) None of the above

C

One p-n junction of a transistor is _______-biased and the other one is _______-biased in the active region.

A) reverse, reverse

B) forward, forward

C) reverse, forward

D) None of the above

B

he magnitude of the base current is typically on the order of _______ as compared to _______ for the emitter.

A) µA, µA

B) µA, mA

C) mA, µA

D) mA, mA

B

The base current is the _______ of the emitter and collector currents.

A) sum

B) difference

C) product

D) None of the above

A

The _______ region is the region normally employed for linear (undistorted) amplifiers.

A) active

B) cutoff

C) saturation

D) All of the above

C

In the cutoff region the collector-base junction is _______-biased and the base-emitter junction is _______-biased for a transistor.

A) reverse, forward

B) forward, reverse

C) reverse, reverse

D) forward, forward

D

In the saturation region the collector-base junction is _______-biased and the base-emitter junction is _______-biased for a transistor.

A) reverse, forward

B) forward, reverse

C) reverse, reverse

D) forward, forward

B

For practical transistors the level of alpha typically extends from _____ to _____ with most approaching the higher end of the range.

A) 0.0, 1

B) 0.90, 0.998

C) 50, 400

D) None of the above

C

Typical values of voltage amplification for the common-base configurations vary from _______ and the current gain is always _______.

A) less than 1, 50 to 300

B) 50 to 300, larger than 1

C) 50 to 300, less than 1

D) larger than 1, 50 to 300

C

If a value of beta.gif is specified for a particular transistor configuration it will normally be used for _____ calculations.

A) ac

B) dc

C) ac and dc

D) None of the above

B

The common-collector configuration has a ______ input impedance and a ______ output impedance.

A) low, high

B) high, low

C) high, high

D) low, low

D

The active region of a transistor is bounded by the _______.

A) cutoff region

B) saturation region

C) power dissipation curve

D) All of the above

B

The "on" and "off" characteristics refer to _____ limits while the small-signal characteristics indicate the parameters of importance to _____ operation.

A) ac, dc

B) dc, ac

C) ac, dc and ac

D) dc and ac, dc

C

The step function (per step) of a curve tracer reveals the scale for _______.

A) collector current IC

B) VCE voltage

C) base current IB

D) All of the above

D

The level of _____ is determined and displayed by advanced digital meters.

A) VCE

B) IB

C) IC

D) βdc

A

The level of _____ is determined and displayed by advanced digital meters if using diode-testing mode.

A) VBE

B) IC

C) IB

D) IE

A

When checking a transistor by ohmmeter, a relatively _______ resistance is displayed for a forward-biased junction and ______ resistance for a reverse-biased junction.

A) low, very high

B) low, low

C) high, high

D) high, very low

B

An OL indication on an advanced digital meter indicates _______ while checking a transistor.

A) forward bias

B) reverse bias

C) definitely a defective transistor

D) None of the above

A

If the positive lead of an ohmmeter is connected to the base and the negative lead to the emitter, a low resistance reading would indicate a ______ transistor and a high resistance reading would indicate a ______ transistor.

A) npn, pnp

B) pnp, npn

C) npn, npn

D) pnp, pnp

B

The leads of a transistor are typically made of _______.

A) gold

B) aluminum

C) nickel

D) All of the above

D

There is(are) _______ in the internal construction of a TO-92 package.

A) gold bond wires

B) a copper frame

C) epoxy encapsulation

D) All of the above