Safety

5 free sample questions of the 36 in this topic. The full set is in the app.

1. Question 1

   Which of the following is a safety hazard of a 12-volt storage battery that lacks internal protection circuitry?

   • A.Touching both terminals with your hands can cause electrical shock
   • B.Shorting the terminals can cause burns, fire, or an explosion
   • C.RF emissions from a nearby transmitter can cause the electrolyte to emit poison gas
   • D.All these choices are correct
   Show answer & explanation

   Answer: B. Shorting the terminals can cause burns, fire, or an explosion

   Shorting the terminals can cause burns, fire, or an explosion. (NCVEC T0A)

   Source: 2026-2030 Technician Class FCC Element 2 Question Pool and Syllabus — Subelement T0, Group T0A, Question T0A01

2. Question 2

   What health hazard is posed by electrical current flowing through the body?

   • A.It may cause injury by heating body tissue
   • B.It may disrupt the electrical functions of cells
   • C.It may cause involuntary muscle contractions
   • D.All these choices are correct
   Show answer & explanation

   Answer: D. All these choices are correct

   All these choices are correct. (NCVEC T0A)

   Source: 2026-2030 Technician Class FCC Element 2 Question Pool and Syllabus — Subelement T0, Group T0A, Question T0A02

3. Question 3

   In the United States, what circuit does black wire insulation indicate in a three-wire 120 V AC cable?

   • A.Neutral
   • B.Hot
   • C.Equipment ground
   • D.Negative
   Show answer & explanation

   Answer: B. Hot

   Hot. (NCVEC T0A)

   Source: 2026-2030 Technician Class FCC Element 2 Question Pool and Syllabus — Subelement T0, Group T0A, Question T0A03

4. Question 4

   What is the purpose of a fuse in an electrical circuit?

   • A.To prevent power supply ripple from damaging a component
   • B.To remove power in case of an overload
   • C.To limit current and prevent shocks
   • D.All these choices are correct
   Show answer & explanation

   Answer: B. To remove power in case of an overload

   To remove power in case of an overload. (NCVEC T0A)

   Source: 2026-2030 Technician Class FCC Element 2 Question Pool and Syllabus — Subelement T0, Group T0A, Question T0A04

5. Question 5

   Why should a 5-ampere fuse never be replaced with a 20-ampere fuse?

   • A.The larger fuse would be likely to blow because it is rated for higher current
   • B.The power supply ripple would greatly increase
   • C.Excessive current could cause a fire
   • D.Voltage drop in the higher current fuse could result in excessively low voltage to the device
   Show answer & explanation

   Answer: C. Excessive current could cause a fire

   Excessive current could cause a fire. (NCVEC T0A)

   Source: 2026-2030 Technician Class FCC Element 2 Question Pool and Syllabus — Subelement T0, Group T0A, Question T0A05

31 more Safety questions are in the app, along with explanations and flashcards for every one.

OnAir is an independent study aid based on the NCVEC 2026-2030 Technician Class question pool and 47 CFR Part 97. It is not affiliated with, endorsed by, or sponsored by the FCC, NCVEC, ARRL, or any government agency.