RF hazards: radiation exposure, proximity to antennas, recognized safe power levels, radiation types, duty cycle
T0C01
What type of radiation are radio signals?
-
A
Gamma radiation
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B
Ionizing radiation
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C
Alpha radiation
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D
Non-ionizing radiation
T0C02
Which of the following bands has the lowest maximum permissible exposure for RF safety?
-
A
3.5 MHz
-
B
50 MHz
-
C
440 MHz
-
D
1296 MHz
T0C03
How does the allowable power density for RF safety change if duty cycle changes from 100 percent to 50 percent?
-
A
It increases by a factor of 3
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B
It decreases by 50 percent
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C
It increases by a factor of 2
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D
There is no adjustment allowed for lower duty cycle
T0C04
What factors affect the RF exposure of people near an amateur station antenna?
-
A
Frequency and power level of the RF field
-
B
Distance from the antenna to a person
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C
Radiation pattern of the antenna
-
D
All these choices are correct
T0C05
Why do exposure limits vary with frequency?
-
A
Lower frequency RF fields have more energy than higher frequency fields
-
B
Lower frequency RF fields do not penetrate the human body
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C
Higher frequency RF fields are transient in nature
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D
The human body absorbs more RF energy at some frequencies than at others
T0C06
Which of the following is an acceptable method to determine whether 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
T0C07
What hazard is created by touching an antenna during a transmission?
-
A
Electrocution
-
B
RF burn to skin
-
C
Exposure to ionizing radiation
-
D
All these choices are correct
T0C08
Which of the following actions can reduce exposure to RF radiation?
-
A
Relocate antennas
-
B
Relocate the transmitter
-
C
Increase the duty cycle
-
D
All these choices are correct
T0C09
How can you make sure your station stays in compliance with RF safety regulations?
-
A
By informing the FCC of any changes made in your station
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B
By re-evaluating the station whenever an item in the transmitter or antenna system is changed
-
C
By making sure your antennas have low SWR
-
D
By using only Underwriter Laboratories approved transmitting equipment
T0C10
Why is duty cycle one of the factors used to determine safe RF radiation exposure levels?
-
A
It affects the average exposure to radiation
-
B
It affects the peak exposure to radiation
-
C
It takes into account the antenna feed line loss
-
D
It takes into account the thermal effects of the final amplifier
T0C11
What is the definition of duty cycle during the averaging time for RF exposure?
-
A
The difference between the lowest and highest power output of a transmitter
-
B
The difference between the PEP and the average power output of a transmitter
-
C
The percentage of time that a transmitter is transmitting
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D
The percentage of time that a transmitter is not transmitting
T0C12
How does RF radiation differ from ionizing radiation (radioactivity)?
-
A
RF radiation does not have sufficient energy to cause chemical changes in cells and damage DNA
-
B
RF radiation can only be detected with an RF dosimeter
-
C
RF radiation is limited in range to a few feet
-
D
RF radiation is perfectly safe
T0C13
Who is responsible for ensuring that no person is exposed to RF energy above the FCC exposure limits?
-
A
The FCC
-
B
The station licensee
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C
Anyone who is near an antenna
-
D
The local zoning board