Technician T3B: Radio waves, wavelength and frequency
These are the 12 official questions in group T3B of the 2026–2030 Technician question pool, with the correct answer marked and a plain-English explanation of why it's right. The real exam asks one question from this group.
- T3B01Question 1
What is the relationship between the electric and magnetic fields of an electromagnetic wave?
- AThey travel at different speeds
- BThey are in parallel
- CThey revolve in opposite directions
- DThey are at right angles Correct
Why: The electric and magnetic fields of a radio wave are at right angles to each other.
- T3B02Question 2
What property of a radio wave defines its polarization?
- AThe orientation of the electric field Correct
- BThe orientation of the magnetic field
- CThe ratio of the energy in the magnetic field to the energy in the electric field
- DThe ratio of the velocity to the wavelength
Why: Polarization is the orientation of the electric field.
- T3B03Question 3
What are the two components of a radio wave?
- AImpedance and reactance
- BVoltage and current
- CElectric and magnetic fields Correct
- DIonizing and non-ionizing radiation
Why: A radio wave is made of an electric field and a magnetic field.
- T3B04Question 4
What is the velocity of a radio wave traveling through free space?
- ASpeed of light Correct
- BSpeed of sound
- C0.86 times the speed of light
- D1.86 times the speed of sound
Why: Radio waves are electromagnetic waves, so in free space they travel at the speed of light.
- T3B05Question 5
What is the relationship between wavelength and frequency?
- AWavelength gets longer as frequency increases
- BWavelength gets shorter as frequency increases Correct
- CWavelength is constant at all frequencies
- DWavelength and frequency increase as path length increases
Why: As frequency goes up, wavelength gets shorter.
- T3B06Question 6
What is the formula for converting frequency to approximate wavelength in meters?
- AWavelength in meters equals frequency in hertz multiplied by 300
- BWavelength in meters equals frequency in hertz divided by 300
- CWavelength in meters equals frequency in megahertz divided by 300
- DWavelength in meters equals 300 divided by frequency in megahertz Correct
Why: Wavelength in meters = 300 ÷ frequency in MHz.
- T3B07Question 7
In addition to frequency, which of the following is used to identify amateur radio bands?
- AThe approximate wavelength in meters Correct
- BTraditional letter/number designators
- CChannel numbers
- DAll these choices are correct
Why: Bands are also named by approximate wavelength, like 2 meters or 70 centimeters.
- T3B08Question 8
What frequency range is referred to as VHF?
- A30 kHz to 300 kHz
- B30 MHz to 300 MHz Correct
- C300 kHz to 3000 kHz
- D300 MHz to 3000 MHz
Why: VHF is 30 to 300 MHz.
- T3B09Question 9
What frequency range is referred to as UHF?
- A30 to 300 kHz
- B30 to 300 MHz
- C300 to 3000 kHz
- D300 to 3000 MHz Correct
Why: UHF is 300 to 3,000 MHz.
- T3B10Question 10
What frequency range is referred to as HF?
- A300 to 3000 MHz
- B30 to 300 MHz
- C3 to 30 MHz Correct
- D300 to 3000 kHz
Why: HF is 3 to 30 MHz.
- T3B11Question 11
What is the approximate velocity of a radio wave in free space?
- A150,000,000 meters per second
- B300,000,000 meters per second Correct
- C300,000,000 miles per hour
- D150,000,000 miles per hour
Why: Radio waves travel at the speed of light, about 300,000,000 meters per second.
- T3B12Question 12
Which of these frequencies travels at the highest velocity in free space?
- AMicrowaves
- BUHF
- CVHF
- DAll radio frequencies travel at the same velocity Correct
Why: Every radio frequency travels at the same speed in free space, the speed of light.