ETC ETC Electrical & Electronic Systems

Question 1

What is the standard US residential single-phase voltage supplied to most homes?

Accepted Answer

120/240 V

Answer

US residential service is single-phase 120/240 V, providing 120 V for general outlets and 240 V for large appliances.

Question 2

Which electrical code governs the installation of electrical wiring and equipment in the United States?

Accepted Answer

NFPA 70 (NEC)

Answer

NFPA 70, the National Electrical Code (NEC), is the primary standard for safe electrical installation in the US.

Question 3

In Ohm's Law, if a circuit has a voltage of 120 V and a resistance of 60 ohms, what is the current?

Accepted Answer

2 A

Answer

Ohm's Law states I = V/R; 120 V divided by 60 ohms equals 2 A.

Question 4

What does GFCI stand for in electrical safety?

Accepted Answer

Ground Fault Circuit Interrupter

Answer

A Ground Fault Circuit Interrupter detects imbalances in current flow and quickly shuts off power to prevent electrocution.

Question 5

What is the purpose of a disconnect switch in an electrical panel?

Accepted Answer

To safely de-energize a circuit for maintenance

Answer

A disconnect switch allows a technician to safely isolate and de-energize a circuit before performing maintenance.

(ETC) Engineering Technician Certification Practice Test