Electronics Engineering Coaching Materials: Section 4 Module 2

This is the Section 4 Module 2 of the compiled Electronics Coaching Materials taken from different sources including but not limited to Electronics books, past Board Exams Questions, Journals and other Electronics References. This particular Coaching Notes in Electronics Engineering has random Questions and Answers in random topics. Make sure to familiarize each questions to increase the chance of passing the ECE Board Exam.

Electronics Engineering Coaching: Section 4 Module 2

AC/DC CIRCUITS

1. A complex circuit simplified to an open circuit voltage and open circuit resistor

THEVENIN’S THEOREM

2. What theorem is used in solving electrical circuit swith several voltage sources?

SUPERPOSITION

3. Refer to current pulses that flow in the same direction

PULSATING DIRECT CURRENT

4. Relays are used to.

DECREASE THE CURRENT IN THE CIRCUIT

5. Damage to the electric component occurs at what minimum electrostatic potential.

35 VOLTS

6. Type of converter used to convert DC voltage to AC voltage

INVERTER

7. A process of converting an alternating current to a pulsating dc.

RECTIFICATION

8. In circuit, it is use to convert AC voltage to DC voltage

RECTIFIER

9. Vrms in an ac…

HOLDING VOLTAGE

10. A value at any instant time

INSTANTANEOUS VALUE

11. Voltage/current along at any instant of time

INSTANTANEOUS

12. Frequency is inversely proportional to . . . slope

SINE WAVE

13. What is the amplitude of two waves with equal amplitude and frequency but opposite in phase

ZERO ( THE SIGNAL WILL CANCEL EACH OTHER)

14. Represents a cycle of degree of phase

1/360

15. The angular frequency of a 60-Hz AC source

377 RAD/SEC

16. Two same frequencies 1/10 cycle apart has a phase difference of

36 DEGREES

17. Two AC signals with the same frequency but differs in phase by 1/10 of a cycle. What is the difference of two signals?

36 degrees

18. The length of time between a point in one cycle and the same point in the next cycle of an AC wave is the ___

PERIOD

19. When a capacitor is placed in an AC supply, the current ____ voltage by 90 degrees

LEADS

20. The absolute value of the impedance in a circuit increases _____

THE FLOW OF AC DECREASES

21. Relay that conducts only when current is supplied.

NORMALLY OPEN

22. When there is a reactance in the load where the transformer is connected

PERFECT IMPEDANCE MATCH CANNOT BE OBTAINED

POWER SUPPLY / GENERATORS and MOTORS

1. Efficiency of silicon solar cells _____

22%

2. Efficiency of a full wave rectifier

81.2%

3. Efficiency of a half wave rectifier

40.6%

4. In full-wave rectifier, the ripple is ________ than that of a half-wave rectifier.

TWICE

5. Combination of cells connected in series

BATTERY

6. A battery consists of_____________.

NUMBER OF CELLS

7. A lantern battery is most like to be found in __

A TWO WAY RADIO

8. A nickel-iron cell has a nominal voltage of 1.2V. It is also known as ___ cell.

EDISON

9. A modified version of the UPS which is used as back-up power supply

STAND-BY POWER SUPPLY

10. Where would you most likely find a lead-acid battery?

IN AN UNINTERRUPTABLE POWER SUPPLY

11. As a rule of thumb, Power rectifier … back-to-front or front-to-back ratio is ____

10-to-1

12. As a rule of thumb, Signal diode … back-to-front or front-to-back ratio is _____

300-to-1

13. A modified UPS wherein the power line itself serves as a back-up for the system

STANDBY POWER SUPPLY

14. In a Carbon zinc battery, zinc serves as

NEGATIVE CATHODE

15. What is the advantage of Alkaline cell over zinc-carbon cell

ALKALINE CELL WORKS WITH LOW TEMPERATURE

16. An advantage of alkaline cell over zinc-carbon cells

THE ALKALINE CELL CAN DELIVER USEFUL CURRENT AT LOWER TEMPERATURES

17. (mahabang intro…..tapos,)If you need low volume, low mass, and do not need regular maintenance, what type of battery should you use?

LITHIUM BATTERY

18. Typical output of silicon photovoltaic cell

0.6 VOLTS

19. Maximum theoretical efficiency of solar cell

22%

20. The electrical power that a solar panel can provide either in direct sunlight depends on all of the following factors except

AC VOLTAGE APPLIED DIRECT TO PANEL

21. A variable positive regulator.

317 (usually LM 317)

22. A fixed positive regulator

74XX

23. The most efficient regulator, used for high voltage and high current application

SWITCHING REGULATOR

24. Regulator that dissipates less power and less heat

SWITCHING REGULATOR

25. Linear regulator in which the load connected to the unregulated source must be kept constant

SHUNT REGULATOR

26. A regulator that dissipates less heat and less power

SWITCHING REGULATOR

27…frequency varies…

VOLTAGE CONTROLLED RECTIFIER

28. In a rectifier, to have a desired dc voltage output, ________ should be installed.

FILTER CAPACITOR

29. A current surge takes place when a power supply is first turned on because, ___

FILTER CAPACITOR MUST BE INITIALLY CHARGED

30. The part of a power supply immediately preceding the regulator is

FILTER

31. It is not a main component of an AC power supply.

RECTIFIER

32. A plate-type capacitor with two stator sections and a single rotor section common on both stators

BUTTERFLY CAPACITOR

33. If there is reactance in the load to which a transformer is connected, then _____

A PERFECT IMPEDANCE MATCH CANNOT BE OBTAINED

34. When reactance exists in the output of a ??? transformer,

THERE WILL ALWAYS BE AN IMPEDANCE MISMATCH

35. Maximum efficiency of half-wave rectifier

40.6 %

36. One revolution is equal to 200 steps. What is the angle movement?

1.8

37. Which is easily filtered by a power supply?

HIGH FREQUENCY PULSATING DC

38. Which motor is the best choice for handling heavy loads at short duration

COMMULATIVELY COMPOUNDED

39. In shunt wound with constant speed, as the current increases the _____

TERMINAL VOLTAGE INCREASES

40. The spin of a motor is 100% until the motor reach

LOW VALUE

41. Maintains the current in varying load better than series

SHUNT

42. Two primary parts of a rotating generator

PERMANENT OR TEMPORARY MAGNETS AND ARMATURE WINDINGS

43. Alternative to DC Motor as actuator.

PIEZO MOTOR OR ULTRASONIC MOTOR

44. Compared to straight cut spur gear, helical gear has_____________.

LESS BACKLASH

45. The current in secondary winding is greater than primary winding in step-up transformer.  This statement is _______.

FALSE

46. A transducer which converts linear motion of the object mechanically connected to it to electrical signal

LINEAR VARIABLE DIFFERENTIAL TRANSFORMER (LVDT)

47. A shell method in transformer winding

PULSE MAXIMUM COUPLING

48. The electronic transfer of energy from one stage to another is called_______.

COUPLING

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