IST Electrical and Electronic Knowledge 2

Question 1

What does AC stand for in electrical systems?

Accepted Answer

Alternating Current

Answer

Alternating Circuit

Answer

Amplified Current

Answer

Automatic Control

Question 2

What is the standard frequency of AC power in the United States?

Accepted Answer

60 Hz

Answer

50 Hz

Answer

120 Hz

Answer

240 Hz

Question 3

What is the function of a transformer in an electrical system?

Accepted Answer

Change voltage levels from one level to another

Answer

Convert AC to DC power

Answer

Measure electrical current flow

Answer

Regulate frequency of the power supply

Question 4

A motor nameplate shows 480V/3-phase. What does '3-phase' indicate?

Accepted Answer

The motor uses three separate AC waveforms offset by 120 degrees

Answer

The motor has three speed settings

Answer

The motor requires three separate ground wires

Answer

The motor operates at three distinct power levels

Question 5

If two 10-Ohm resistors are connected in parallel, what is the total resistance?

Accepted Answer

5 Ohms

Answer

10 Ohms

Answer

20 Ohms

Answer

0.1 Ohms

Question 6

What instrument is used to measure electrical voltage?

Accepted Answer

Voltmeter

Answer

Ammeter

Answer

Ohmmeter

Answer

Wattmeter