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

Electronics and Circuits: Test Questions and Answers, Exams of Electrical and Electronics Engineering

A comprehensive set of questions and answers related to electronics and circuits, covering topics such as solenoids, relays, diodes, op amps, power supplies, and voltage regulators. It is a valuable resource for students studying electronics and can be used for self-assessment or exam preparation.

Typology: Exams

2024/2025

Available from 02/11/2025

essay-writers
essay-writers 🇺🇸

3.8

(91)

1.9K documents

1 / 14

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
ATT TEST 8 ACTUAL TEST 2025 | ALL QUESTIONS
AND CORRECT ANSWERS | GRADED A+ | VERIFIED
ANSWERS | LATEST TEST (JUST RELEASED)
What is difference between solenoid and relay? ---------CORRECT
ANSWER-----------------Solenoid has movable core (plunger), core tries to
center itself in mag field
What are typical faults in relays? ---------CORRECT ANSWER-----------------
Faulted magnetic coil or faulted contacts
What fault is caused by current flowing in one direction in contacts? ---------
CORRECT ANSWER-----------------Coned or cratered contacts
What is used to fix burned contacts? ---------CORRECT ANSWER-------------
----Burnishing tool
What is TS procedure for relays? ---------CORRECT ANSWER-----------------
Check inputs, check outputs
What is TS procedure for electrical circuits? ---------CORRECT ANSWER---
--------------Analyze, check setup, calculate/measure, check results
What are most common faults in electrical circuits? ---------CORRECT
ANSWER-----------------Open/short
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe

Partial preview of the text

Download Electronics and Circuits: Test Questions and Answers and more Exams Electrical and Electronics Engineering in PDF only on Docsity!

ATT TEST 8 ACTUAL TEST 2025 | ALL QUESTIONS

AND CORRECT ANSWERS | GRADED A+ | VERIFIED

ANSWERS | LATEST TEST (JUST RELEASED)

What is difference between solenoid and relay? ---------CORRECT ANSWER-----------------Solenoid has movable core (plunger), core tries to center itself in mag field What are typical faults in relays? ---------CORRECT ANSWER----------------- Faulted magnetic coil or faulted contacts What fault is caused by current flowing in one direction in contacts? --------- CORRECT ANSWER-----------------Coned or cratered contacts What is used to fix burned contacts? ---------CORRECT ANSWER------------- ----Burnishing tool What is TS procedure for relays? ---------CORRECT ANSWER----------------- Check inputs, check outputs What is TS procedure for electrical circuits? ---------CORRECT ANSWER--- --------------Analyze, check setup, calculate/measure, check results What are most common faults in electrical circuits? ---------CORRECT ANSWER-----------------Open/short

If a diode is shorted in power supply what happens? ---------CORRECT ANSWER-----------------LED wont illuminate, AC isnt converted to DC If diode is open in power supply what happens? ---------CORRECT ANSWER-----------------LED wont illuminate, pulsating DC missing cycle What are three circuits in an op amp? ---------CORRECT ANSWER----------- ------Differential amp, common collector amp, push pull amp What is the purpose of op amps? ---------CORRECT ANSWER----------------- Use two inputs to determine an output (versatile, replace transistors) What does + indicate on op amp? ---------CORRECT ANSWER----------------

  • Non-inverting What does - indicate on op amp? ---------CORRECT ANSWER----------------- Inverting Using both inputs produces what type of amp? ---------CORRECT ANSWER-----------------Diffential Connecting several inputs to inverting (-) input produces which type of amp? ---------CORRECT ANSWER-----------------Summing amp

What is the purpose of a power supply? ---------CORRECT ANSWER-------- ---------To convert AC power into smooth DC power What does the input of a power supply do? ---------CORRECT ANSWER---- -------------Step up or down the AC input voltage What does the rectifier do in a power supply? ---------CORRECT ANSWER- ----------------Changes AC into pulsating DC What does the filter do in a power supply? ---------CORRECT ANSWER----- ------------Changes pulsating DC into smooth DC How type of components do filters use? ---------CORRECT ANSWER--------- --------Reactive components What does a regulator do in a power supply? ---------CORRECT ANSWER-- ---------------maintains the output voltage at a constant level despite changes in load current What does the protection circuit do in power supply? ---------CORRECT ANSWER-----------------Prevents damage to power supply if load becomes faulty, limits or disables output

The half wave rectifier is the same as what circuit? ---------CORRECT ANSWER-----------------Series limiter Which rectifier is the least efficient using only half the input? --------- CORRECT ANSWER-----------------Half-wave Which two rectifiers require two input signals 180 degrees out of phase? --- ------CORRECT ANSWER-----------------Full-wave and bridge Which rectifier uses a center tapped transformer? ---------CORRECT ANSWER-----------------Full wave How is frequency determined for half wave rectifier? ---------CORRECT ANSWER-----------------Output frequency is same as input frequency How is frequency determined for full wave rectifier? ---------CORRECT ANSWER-----------------Output is twice the input frequency How is frequency determined for bridge rectifier? ---------CORRECT ANSWER-----------------Output is twice the input frequency What is the purpose of series voltage regulators? ---------CORRECT ANSWER-----------------To adjust voltage drop to maintain V out at constant level

In parallel voltage regulator, V out decreases when what happens? --------- CORRECT ANSWER-----------------When DC input decreases or load current increases What makes a zener diode different from junction diode? ---------CORRECT ANSWER-----------------Zener diode is designed operate in breakdown When does zener diode conduct reverse current? ---------CORRECT ANSWER-----------------When reverse bias voltage is HIGHER than Vz (diode acts like resistor) When diode is forward biased, what is the output voltage in shunt regulator? ---------CORRECT ANSWER-----------------0.7V When reverse biased lower than Vz, what happens to zener diode? --------- CORRECT ANSWER-----------------Acts like an open If reverse biased lower than Vz, what is output voltage of shunt regulator? - --------CORRECT ANSWER-----------------Output is applied voltage When reverse biased higher than Vz, what is the output voltage of shunt regulator? ---------CORRECT ANSWER-----------------Vz Which component changes resistances to maintain constant V out (zener diode regulator)? ---------CORRECT ANSWER-----------------Q

Which component sets output voltage (zener diode regulator)? --------- CORRECT ANSWER-----------------D1 (holds Q1 at Vz) The voltage on emitter is established by what in zener diode regulator? ----- ----CORRECT ANSWER-----------------Action of Q If voltage increases what must happen to keep output voltage constant (zener diode regulator)? ---------CORRECT ANSWER-----------------Q collector-emitter resistance must increase If voltage decreases what must happen to keep output voltage constant (zener diode regulator)? ---------CORRECT ANSWER-----------------Q collector-emitter resistance must decrease In a voltage regulator, which component maintains a constant V out? --------

  • CORRECT ANSWER-----------------Q In a voltage regulator, which components set voltage? ---------CORRECT ANSWER-----------------D1 and Q What does R2 do in voltage regulator? ---------CORRECT ANSWER---------- -------Varies conduction of Q2 (changes Vce)

What two conditions cause Vout to DECREASE in voltage regulator? --------

  • CORRECT ANSWER-----------------Input voltage decreases or load current increases What are the most common faults in voltage regulators? ---------CORRECT ANSWER-----------------Semiconductor components (transistors/diodes) In a zener diode regulator, which faults cause output voltage to approach applied voltage? ---------CORRECT ANSWER-----------------D1 open, Short between Collector-Emitter In zener diode regulator, which faults cause output voltage to be 0V? --------
  • CORRECT ANSWER-----------------D1 short/R1 Open, open between Base- Emitter Which fault in zener diode regulation can damage diode? --------- CORRECT ANSWER-----------------R1 short How do you calculate base voltage of Q1 in voltage regulator? --------- CORRECT ANSWER-----------------Vz + Vce = Vb Which fault in zener diode /voltage regulator causes Q1 base voltage to increase and approach saturation? ---------CORRECT ANSWER--------------- --D1 Open

Which fault in zener diode / voltage regulator causes Q1 base voltage to decreases and approach cutoff? ---------CORRECT ANSWER----------------- D1 short (no output volts) Which faults cause output voltage to approach applied volts in voltage regulator? ---------CORRECT ANSWER-----------------D1 open, R1 short, Q short Collector-Emitter Which faults cause output voltage to be 0V in voltage regulator? --------- CORRECT ANSWER-----------------R1 open, open Q1 base-emitter Which faults cause output voltage to decrease in voltage regulator? --------- CORRECT ANSWER-----------------D1 short, Q2 short What are two benefits of IC regulators? ---------CORRECT ANSWER--------- --------Safe/durable (thermal overload protection/current limiting protection) A constant 12 VDC output is maintained when input is between what values? (IC regulator) ---------CORRECT ANSWER-----------------14.5-30V What is max current output in 7812 IC regulator? ---------CORRECT ANSWER-----------------1.5A (RL never below 8 ohms) What is the purpose of unijunction transistors? ---------CORRECT ANSWER-----------------Switch voltage, turn on when input exceeds specific level

What happens when gate current is removed in SCR? ---------CORRECT ANSWER-----------------Nothing, diode is latched on How is SCR turned off? ---------CORRECT ANSWER-----------------Current flow must be interrupted with switch or by shorting anode to cathode What is the range of trigger currents in SCR? ---------CORRECT ANSWER- ----------------2mA to 20mA What is a purpose of relays? ---------CORRECT ANSWER----------------- Used for applying power to circuits or controlling signal flow What are two benefits of relays? ---------CORRECT ANSWER----------------- Can handle higher levels of current, make large power transfers possible How are relays shown on schematics? ---------CORRECT ANSWER---------- -------De-Energized Saying contacts are normally closed or normally open refers to them in which state? ---------CORRECT ANSWER-----------------De-energized What are 4 parts of relay? ---------CORRECT ANSWER----------------- magnetic coil, contacts, armature, spring

What replaces armature in multipole relays? ---------CORRECT ANSWER--- --------------Clapper and push rod What is one type of time delay relay? ---------CORRECT ANSWER------------ -----Bimetallic thermal relay