Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Transistor Amplifier Fundamentals: A Comprehensive Guide with Questions and Answers, Exams of Electrical and Electronics Engineering

A comprehensive overview of transistor amplifier fundamentals, covering various aspects such as amplifier classes, biasing techniques, coupling methods, and troubleshooting. It includes a series of questions and answers that test understanding of key concepts and principles. Suitable for students studying electronics or related fields.

Typology: Exams

2024/2025

Available from 02/11/2025

essay-writers
essay-writers 🇺🇸

3.8

(91)

1.9K documents

1 / 18

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
ATT TEST 5 NEWEST TEST 2025 | ALL QUESTIONS
AND CORRECT ANSWERS | GRADED A+ | LATEST
TEST | VERIFIED ANSWERS
Which class of amp is more efficient than class A and has higher fidelity
than class B? ---------CORRECT ANSWER-----------------Class AB
Which class of amp has the best efficiency but worst fidelity? ---------
CORRECT ANSWER-----------------Class C
What is DC bias at for class C amp? ---------CORRECT ANSWER-------------
----BELOW cutoff
Collector current flows for how much of input signal (Class C amp)? ---------
CORRECT ANSWER-----------------25%
What amp configuration has the best values and is most commonly used? -
--------CORRECT ANSWER-----------------Common emitter
Which is the only amp configuration to INVERT the output signal? ---------
CORRECT ANSWER-----------------Common emitter
Which amp configuration is used to drive current? ---------CORRECT
ANSWER-----------------Common collector
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff
pf12

Partial preview of the text

Download Transistor Amplifier Fundamentals: A Comprehensive Guide with Questions and Answers and more Exams Electrical and Electronics Engineering in PDF only on Docsity!

ATT TEST 5 NEWEST TEST 2025 | ALL QUESTIONS

AND CORRECT ANSWERS | GRADED A+ | LATEST

TEST | VERIFIED ANSWERS

Which class of amp is more efficient than class A and has higher fidelity than class B? ---------CORRECT ANSWER-----------------Class AB Which class of amp has the best efficiency but worst fidelity? --------- CORRECT ANSWER-----------------Class C What is DC bias at for class C amp? ---------CORRECT ANSWER------------- ----BELOW cutoff Collector current flows for how much of input signal (Class C amp)? --------- CORRECT ANSWER-----------------25% What amp configuration has the best values and is most commonly used? - --------CORRECT ANSWER-----------------Common emitter Which is the only amp configuration to INVERT the output signal? --------- CORRECT ANSWER-----------------Common emitter Which amp configuration is used to drive current? ---------CORRECT ANSWER-----------------Common collector

Which amp configuration has large voltage gain? ---------CORRECT ANSWER-----------------common base In common emitter amps, small inputs control what type of outputs? --------- CORRECT ANSWER-----------------Large, inverted outputs Which components establish base bias in common emitter circuit? --------- CORRECT ANSWER-----------------R1 and R Which components provide self biasing in common emitter circuit? --------- CORRECT ANSWER-----------------R4 and C C1 and C2 input/output coupling capacitors do what in common emitter circuits? ---------CORRECT ANSWER-----------------Pass AC and block DC A transistor at cutoff bias acts like what? ---------CORRECT ANSWER--------


What is DC bias for a Class A amp? ---------CORRECT ANSWER------------- ----ABOVE cutoff (like AB) What is the purpose of cascade (multistage) amps? ---------CORRECT ANSWER-----------------To increase gain

What is the effect on LOW frequency in RC coupled amps? Are individual stages affected? ---------CORRECT ANSWER-----------------Low frequency decreases total gain but individual stages are NOT affected What happens if frequency is too HIGH in RC coupled amps? --------- CORRECT ANSWER-----------------Reduces total gain What happens if Vpp is too LARGE in RC coupled amps? Are individual stages affected? ---------CORRECT ANSWER-----------------Output is distorted due to clipping and total gain is reduced. Stage gains are LOW What is the purpose of diode limiters? ---------CORRECT ANSWER----------- ------to limit the amplitude of input signal When does limiting occur in a series limiter? ---------CORRECT ANSWER--- --------------When the diode is reverse biased What type of signal reverse biases a series negative limiter? --------- CORRECT ANSWER-----------------Negative signals When does limiting occur in parallel limiters? ---------CORRECT ANSWER-- ---------------When diode is forward biased

What happens when circuit bias is added to limiter circuits? --------- CORRECT ANSWER-----------------partial alterations are eliminated by raising/lowering limits from 0V What is the purpose of diode clampers? ---------CORRECT ANSWER-------- ---------To clamp AC signal AT a DC output level What three components make up clamper circuit? ---------CORRECT ANSWER-----------------capacitor, resistor, diode When is the capacitor able to quickly charge in clamper circuit? --------- CORRECT ANSWER-----------------When the diode is forward biased (low resistance) What is the purpose of transistors? ---------CORRECT ANSWER--------------- --to control currents (signals) The emitter to base is always (forward/reverse) biased? ---------CORRECT ANSWER-----------------Forward (low ohms) The collector to base is always (forward/reverse) biased? --------- CORRECT ANSWER-----------------Reverse (high ohms) Which part of a transistor is heavily doped? ---------CORRECT ANSWER---- -------------Emitter

When saturated the transistor acts like a what? ---------CORRECT ANSWER-----------------Short What is cutoff bias? ---------CORRECT ANSWER-----------------The point where base bias reverse biases the emitter base junction stopping base current and collector current Alpha should never exceed what value? ---------CORRECT ANSWER-------- --------- 1 Beta should be around what values? ---------CORRECT ANSWER------------- ---- 20 - 400 Three types of bias circuits? ---------CORRECT ANSWER----------------- Fixed, self, combination What is the disadvantage of fixed biasing? ---------CORRECT ANSWER----- ------------Temperature sensative What are an advantage and disadvantage of self biasing? --------- CORRECT ANSWER-----------------Fixes temperature issues but lowers beta

Which type of biasing includes a voltage divider? ---------CORRECT ANSWER-----------------Combination How many classes of amps are there? ---------CORRECT ANSWER---------- ------- 4 Collector current in class A amps flows for how much of input signal? --------

  • CORRECT ANSWER-----------------100% Which class of amp has the best fidelity and low distortion? --------- CORRECT ANSWER-----------------Class A What is DC bias for a class B amp? ---------CORRECT ANSWER-------------- ---At cutoff (0.6V) Collector current flows for how much of input signal (Class B amp)? --------- CORRECT ANSWER-----------------50% What is DC bias for class AB amp? ---------CORRECT ANSWER-------------- ---ABOVE cutoff Collector current flows for how much of input signal (class AB amp)? --------
  • CORRECT ANSWER-----------------75%

When are DC bias voltage measurements taken when troubleshooting a multistage amp? ---------CORRECT ANSWER-----------------After faulty stage is found What type of measurements identify faulty components? ---------CORRECT ANSWER-----------------Resistance MOST faults in multistage amps cause what? ---------CORRECT ANSWER- ----------------Change in DC bias levels What are common faults in multistage amps? (4) ---------CORRECT ANSWER-----------------Failed transistor, opens, shorts, changed value Which coupling method has NO reactive components? ---------CORRECT ANSWER-----------------Direct What are push pull amps used for? ---------CORRECT ANSWER--------------- --Power amplification What is a disadvantage of common emitter push pull amps? --------- CORRECT ANSWER-----------------Expensive due to transformers, needs more room What is a general Av gain for common collectors? ---------CORRECT ANSWER-----------------Av = 1

What is the base connected to in fixed biasing? ---------CORRECT ANSWER-----------------Vcc What does the tab indicate on transistors? ---------CORRECT ANSWER-----


Transistor amplifiers require what type of signal to function? --------- CORRECT ANSWER-----------------DC bias and AC input signals What changes are necessary for amplification to occur? ---------CORRECT ANSWER-----------------Small change in base voltage, large change in collector current What amplifier has the best fidelity? ---------CORRECT ANSWER-------------- ---class A What amplifier has the best efficiency? ---------CORRECT ANSWER---------- -------class C When an input is applied across the emitter to base PN Junction, what is the relative resistance? ---------CORRECT ANSWER-----------------low

The suppressor grid reduces the effects of? ---------CORRECT ANSWER--- --------------secondary emission How many electrodes does a pentode have? ---------CORRECT ANSWER-- --------------- 5 What electron-tube amplifier configurations provides a 180 degrees phase shift from the input to the output? ---------CORRECT ANSWER----------------- common cathode What component supplies the electrons for the electron beam? --------- CORRECT ANSWER-----------------cathode What term is used to describe screens that produce only one color? --------- CORRECT ANSWER-----------------monochrome The _________ coating returns the secondary electrons to the power supply. ---------CORRECT ANSWER-----------------aquadag The set of coils which produces a vertical magnetic field is used to deflect the beam? ---------CORRECT ANSWER-----------------horizontally What happens in a transistor when the saturation point is reached? --------- CORRECT ANSWER-----------------Ic stops increasing

What happens in a transistor when the base voltage reverse biases the emitter to base PN junction? ---------CORRECT ANSWER----------------- cutoff occurs _______ is the ratio of Ic/Ie ---------CORRECT ANSWER-----------------Alpha What are the two names of the electrodes in an electron tube diode? --------

  • CORRECT ANSWER-----------------plate and cathode How many electrodes does a tetrode have? ---------CORRECT ANSWER--- -------------- 4 When voltage is first applied to a gas filled tube, the gas will: --------- CORRECT ANSWER-----------------oppose current flow A negative potential with respect to the cathode on the control grid will: ----- ----CORRECT ANSWER-----------------repel electrons What component replaced the triode as an amplifier during the solid state revolution? ---------CORRECT ANSWER-----------------transistor The capacitor in a clamper circuit has a fast charge path when the diode is ___________ ---------CORRECT ANSWER-----------------forward biased

In a _____________ amplifier, when the base voltage increases~ the emitter current increases. ---------CORRECT ANSWER----------------- common collector In a _____________ amplifier, when base voltage decreases~ output voltage decreases. ---------CORRECT ANSWER-----------------common collector In a _____________ amplifier, when the emitter voltage increases~ the emitter to base forward bias decreases. ---------CORRECT ANSWER--------- --------common base In a ____________ amplifier, when the emitter voltage increases~ the emitter current decreases. ---------CORRECT ANSWER----------------- common base What type of coupling has the least effect on the collector AC signal for high frequency inputs? ---------CORRECT ANSWER-----------------LC coupling The ____________ amplifier output is controlled by a small input signal. ---- -----CORRECT ANSWER-----------------common emitter What type of output signal is produced by a class C common base amplifier? ---------CORRECT ANSWER-----------------amplified and inverted

In a RC coupled transistor amplifier, what is the result of a low frequency input signal? Stage gains ______, total gain ______, output signal _________ ---------CORRECT ANSWER-----------------good, low, undistorted In a RC coupled transistor amplifier, what is the result of a high VPP input signal? Stage gains ______, total gain ______, output signal _________ --- ------CORRECT ANSWER-----------------low, low, distorted What type of transistors are used in a common collector push-pull amplifier? ---------CORRECT ANSWER-----------------one NPN and one PNP In RC coupled amplifiers, normal operation is verified by comparing measured and calculated: ---------CORRECT ANSWER-----------------total current voltage gain The transistor bias _______________ are made after the faulty stage has been identified ---------CORRECT ANSWER-----------------voltage measurements The common emitter output phase is _____ degrees out of phase --------- CORRECT ANSWER----------------- 180 What class of amplifiers are biased so collector current is zero for half of the input signal? ---------CORRECT ANSWER-----------------class B