FCCライセンス General 7月 8 2024 SUBELEMENT G3B SUBELEMENT G3B G3B – Maximum Usable Frequency; Lowest Usable Frequency; short path and long path propagation; determining propagation conditions; ionospheric refraction 1 / 12 G3B01What is a characteristic of skywave signals arriving at your location by both short-path and long-path propagation? A. Periodic fading approximately every 10 seconds B. Signal strength increased by 3 dB C. The signal might be cancelled causing severe attenuation D. A slightly delayed echo might be heard 2 / 12 G3B02What factors affect the MUF? A. Path distance and location B. Time of day and season C. Solar radiation and ionospheric disturbances D. All these choices are correct 3 / 12 G3B03Which frequency will have the least attenuation for long-distance skip propagation? A. Just below the MUF B. Just above the LUF C. Just below the critical frequency D. Just above the critical frequency 4 / 12 G3B04Which of the following is a way to determine current propagation on a desired band from your station?Use a network of automated receiving stations on the internet to see where your transmissions are being received A. Use a network of automated receiving stations on the internet to see where your transmissions are being received B. Check the A-index C. Send a series of dots and listen for echoes D. All these choices are correct 5 / 12 G3B05How does the ionosphere affect radio waves with frequencies below the MUF and above the LUF? A. They are refracted back to Earth B. They pass through the ionosphere C. They are amplified by interaction with the ionosphere D. They are refracted and trapped in the ionosphere to circle Earth 6 / 12 G3B06What usually happens to radio waves with frequencies below the LUF? A. They are refracted back to Earth B. They pass through the ionosphere C. They are attenuated before reaching the destination D. They are refracted and trapped in the ionosphere to circle Earth 7 / 12 G3B07What does LUF stand for? A. The Lowest Usable Frequency for communications between two specific points B. Lowest Usable Frequency for communications to any point outside a 100-mile radius C. The Lowest Usable Frequency during a 24-hour period D. Lowest Usable Frequency during the past 60 minutes 8 / 12 G3B08What does MUF stand for? A. The Minimum Usable Frequency for communications between two points B. The Maximum Usable Frequency for communications between two points C. The Minimum Usable Frequency during a 24-hour period D. The Maximum Usable Frequency during a 24-hour period 9 / 12 G3B09What is the approximate maximum distance along the Earth’s surface normally covered in one hop using the F2 region? A. 180 miles B. 1,200 miles C. 2,500 miles D. 12,000 miles 10 / 12 G3B10What is the approximate maximum distance along the Earth’s surface normally covered in one hop using the E region? A. 180 miles B. 1,200 miles C. 2,500 miles D. 12,000 miles 11 / 12 G3B11What happens to HF propagation when the LUF exceeds the MUF? A. Propagation via ordinary skywave communications is not possible over that path B. HF communications over the path are enhanced C. Double-hop propagation along the path is more common D. Propagation over the path on all HF frequencies is enhanced 12 / 12 G3B12Which of the following is typical of the lower HF frequencies during the summer? A. Poor propagation at any time of day B. World-wide propagation during daylight hours C. Heavy distortion on signals due to photon absorption D. High levels of atmospheric noise or static あなたのスコアは平均スコアは 41% 0% クイズを再開する Ed 0 コメント
FCCライセンス General 7月 7 2024 SUBELEMENT G0A SUBELEMENT G0A G0A – RF safety principles, rules, and guidelines; routine station evaluation 1 / 12 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 2 / 12 G0A11What precaution should be taken if you install an indoor transmitting 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 3 / 12 G0A10What 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 4 / 12 G0A09What 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 5 / 12 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 6 / 12 G0A07What 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 7 / 12 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 8 / 12 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 9 / 12 G0A04What 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 10 / 12 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 11 / 12 G0A02Which 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 12 / 12 G0A01What 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 あなたのスコアは平均スコアは 50% 0% クイズを再開する Ed 0 コメント
FCCライセンス General 7月 6 2024 SUBELEMENT G9A SUBELEMENT G9A G9A – Feed lines: characteristic impedance and attenuation; standing wave ratio (SWR) calculation, measurement, and effects; antenna feed point matching 1 / 11 G9A11What is the effect of transmission line loss on SWR measured at the input to the line? A. Higher loss reduces SWR measured at the input to the line B. Higher loss increases SWR measured at the input to the line C. Higher loss increases the accuracy of SWR measured at the input to the line D. Transmission line loss does not affect the SWR measurement 2 / 11 G9A10What standing wave ratio results from connecting a 50-ohm feed line to a 10-ohm resistive load? A. 2:1 B. 1:2 C. 1:5 D. 5:1 3 / 11 G9A09What standing wave ratio results from connecting a 50-ohm feed line to a 200-ohm resistive load? A. 4:1 B. 1:4 C. 2:1 D. 1:2 4 / 11 G9A08If the SWR on an antenna feed line is 5:1, and a matching network at the transmitter end of the feed line is adjusted to present a 1:1 SWR to the transmitter, what is the resulting SWR on the feed line? A. 1:1 B. 5:1 C. Between 1:1 and 5:1 depending on the characteristic impedance of the line D. Between 1:1 and 5:1 depending on the reflected power at the transmitter 5 / 11 G9A07What must be done to prevent standing waves on a feed line connected to an antenna? A. The antenna feed point must be at DC ground potential B. The feed line must be an odd number of electrical quarter wavelengths long C. The feed line must be an even number of physical half wavelengths long D. The antenna feed point impedance must be matched to the characteristic impedance of the feed line 6 / 11 G9A06In what units is RF feed line loss usually expressed? A. Ohms per 1,000 feet B. Decibels per 1,000 feet C. Ohms per 100 feet D. Decibels per 100 feet 7 / 11 G9A05How does the attenuation of coaxial cable change with increasing frequency? A. Attenuation is independent of frequency B. Attenuation increases C. Attenuation decreases D. Attenuation follows Marconi’s Law of Attenuation 8 / 11 G9A04What causes reflected power at an antenna’s feed point? A. Operating an antenna at its resonant frequency B. Using more transmitter power than the antenna can handle C. A difference between feed line impedance and antenna feed point impedance D. Feeding the antenna with unbalanced feed line 9 / 11 G9A03What is the nominal characteristic impedance of “window line” transmission line? A. 50 ohms B. 75 ohms C. 100 ohms D. 450 ohms 10 / 11 G9A02What is the relationship between high standing wave ratio (SWR) and transmission line loss? A. There is no relationship between transmission line loss and SWR B. High SWR increases loss in a lossy transmission line C. High SWR makes it difficult to measure transmission line loss D. High SWR reduces the relative effect of transmission line loss 11 / 11 G9A01Which of the following factors determine the characteristic impedance of a parallel conductor feed line? A. The distance between the centers of the conductors and the radius of the conductors B. The distance between the centers of the conductors and the length of the line C. The radius of the conductors and the frequency of the signal D. The frequency of the signal and the length of the line あなたのスコアは平均スコアは 45% 0% クイズを再開する Ed 0 コメント
