All 25 Ham Radio General Class questions for G0 Electrical & RF Safety with the correct answers marked, from the official 2023-2027 question pool. Test yourself with the free practice exam.
G0A01
What is one way that RF energy can affect human body tissue?
A. It heats body tissue ✓
B. It causes radiation poisoning
C. It causes the blood count to reach a dangerously low level
D. It cools body tissue
G0A02
Which of the following is used to determine RF exposure from a transmitted signal?
A. Its duty cycle
B. Its frequency
C. Its power density
D. All these choices are correct ✓
G0A03 · [97.13(c)(1)]
How can you determine that your station complies with FCC RF exposure regulations?
A. By calculation based on FCC OET Bulletin 65
B. By calculation based on computer modeling
C. By measurement of field strength using calibrated equipment
D. All these choices are correct ✓
G0A04
What does “time averaging” mean when evaluating RF radiation exposure?
A. The average amount of power developed by the transmitter over a specific 24-hour period
B. The average time it takes RF radiation to have any long-term effect on the body
C. The total time of the exposure
D. The total RF exposure averaged over a certain period ✓
G0A05 · [97.13(c)(2), 1.1307(b)]
What must you do if an evaluation of your station shows that the RF energy radiated by your station exceeds permissible limits for possible human absorption?
A. Take action to prevent human exposure to the excessive RF fields ✓
B. File an Environmental Impact Statement (EIS-97) with the FCC
C. Secure written permission from your neighbors to operate above the controlled MPE limits
D. All these choices are correct
G0A06 · [97.13(c)(2), 1.1307(1)(b)(3)(i)]
What must you do if your station fails to meet the FCC RF exposure exemption criteria?
A. Perform an RF exposure evaluation in accordance with FCC OET Bulletin 65 ✓
B. Contact the FCC for permission to transmit
C. Perform an RF exposure evaluation in accordance with World Meteorological Organization guidelines
D. Use an FCC-approved band-pass filter
G0A07
What is the effect of modulation duty cycle on RF exposure?
A. A lower duty cycle permits greater power levels to be transmitted ✓
B. A higher duty cycle permits greater power levels to be transmitted
C. Low duty cycle transmitters are exempt from RF exposure evaluation requirements
D. High duty cycle transmitters are exempt from RF exposure requirements
G0A08 · [97.13(c)(2)]
Which of the following steps must an amateur operator take to ensure compliance with RF safety regulations?
A. Post a copy of FCC Part 97.13 in the station
B. Notify neighbors within a 100-foot radius of the antenna of the existence of the station and power levels
C. Perform a routine RF exposure evaluation and prevent access to any identified high exposure areas ✓
D. All these choices are correct
G0A09
What type of instrument can be used to accurately measure an RF field strength?
A. A receiver with digital signal processing (DSP) noise reduction
B. A calibrated field strength meter with a calibrated antenna ✓
C. An SWR meter with a peak-reading function
D. An oscilloscope with a high-stability crystal marker generator
G0A10
What should be done if evaluation shows that a neighbor might experience more than the allowable limit of RF exposure from the main lobe of a directional antenna?
A. Change to a non-polarized antenna with higher gain
B. Use an antenna with a higher front-to-back ratio
C. Take precautions to ensure that the antenna cannot be pointed in their direction when they are present ✓
D. All these choices are correct
G0A11
What precaution should be taken if you install an indoor transmitting antenna?
A. Locate the antenna close to your operating position to minimize feed-line radiation
B. Position the antenna along the edge of a wall to reduce parasitic radiation
C. Make sure that MPE limits are not exceeded in occupied areas ✓
D. Make sure the antenna is properly shielded
G0A12 · [1.1307(1)(b)(3)(i)(A)]
What stations are subject to the FCC rules on RF exposure?
A. All commercial stations; amateur radio stations are exempt
B. Only stations with antennas lower than one wavelength above the ground
C. Only stations transmitting more than 500 watts PEP
D. All stations with a time-averaged transmission of more than one milliwatt ✓
G0B01
Which wire or wires in a four-conductor 240 VAC circuit should be attached to fuses or circuit breakers?
A. Only the hot wires ✓
B. Only the neutral wire
C. Only the ground wire
D. All wires
G0B02
According to the National Electrical Code, what is the minimum wire size that may be used safely for wiring with a 20-ampere circuit breaker?
A. AWG number 20
B. AWG number 16
C. AWG number 12 ✓
D. AWG number 8
G0B03
Which size of fuse or circuit breaker would be appropriate to use with a circuit that uses AWG number 14 wiring?
A. 30 amperes
B. 25 amperes
C. 20 amperes
D. 15 amperes ✓
G0B04
Where should the station’s lightning protection ground system be located?
A. As close to the station equipment as possible
B. Outside the building ✓
C. Next to the closest power pole
D. Parallel to the water supply line
G0B05
Which of the following conditions will cause a ground fault circuit interrupter (GFCI) to disconnect AC power?
A. Current flowing from one or more of the hot wires to the neutral wire
B. Current flowing from one or more of the hot wires directly to ground ✓
C. Overvoltage on the hot wires
D. All these choices are correct
G0B06
Which of the following is covered by the National Electrical Code?
A. Acceptable bandwidth limits
B. Acceptable modulation limits
C. Electrical safety of the station ✓
D. RF exposure limits of the human body
G0B07
Which of these choices should be observed when climbing a tower using a safety harness?
A. Always hold on to the tower with one hand
B. Confirm that the harness is rated for the weight of the climber and that it is within its allowable service life ✓
C. Ensure that all heavy tools are securely fastened to the harness
D. All these choices are correct
G0B08
What should be done before climbing a tower that supports electrically powered devices?
A. Notify the electric company that a person will be working on the tower
B. Make sure all circuits that supply power to the tower are locked out and tagged ✓
C. Unground the base of the tower
D. All these choices are correct
G0B09
Which of the following is true of an emergency generator installation?
A. The generator should be operated in a well-ventilated area ✓
B. The generator must be insulated from ground
C. Fuel should be stored near the generator for rapid refueling in case of an emergency
D. All these choices are correct
G0B10
Which of the following is a danger from lead-tin solder?
A. Lead can contaminate food if hands are not washed carefully after handling the solder ✓
B. High voltages can cause lead-tin solder to disintegrate suddenly
C. Tin in the solder can “cold flow,” causing shorts in the circuit
D. RF energy can convert the lead into a poisonous gas
G0B11
Which of the following is required for lightning protection ground rods?
A. They must be bonded to all buried water and gas lines
B. Bends in ground wires must be made as close as possible to a right angle
C. Lightning grounds must be connected to all ungrounded wiring
D. They must be bonded together with all other grounds ✓
G0B12
What is the purpose of a power supply interlock?
A. To prevent unauthorized changes to the circuit that would void the manufacturer’s warranty
B. To shut down the unit if it becomes too hot
C. To ensure that dangerous voltages are removed if the cabinet is opened ✓
D. To shut off the power supply if too much voltage is produced
G0B13
Where should lightning arrestors be located?
A. Where the feed lines enter the building ✓
B. On the antenna, opposite the feed point
C. In series with each ground lead
D. At the closest power pole ground electrode