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Text File | 1992-01-26 | 13KB | 481 lines

FCC TECHNICIAN Exam Question Pool. Subelement 3AD. Amateur Radio Practice. 4 Questions. --------------------------------------------------- 3AD 1-1.1 C Where should the green wire in an ac line cord be attached in a power supply? A. To the fuse B. To the "hot" side of the power switch C. To the chassis D. To the meter 3AD 1-1.2 D Where should the black (or red) wire in a three-wire line cord be attached in a power supply? A. To the filter capacitor B. To the dc ground C. To the chassis D. To the fuse 3AD 1-1.3 B Where should the white wire in a three-wire line cord be attached in a power supply? A. To the side of the transformer's primary winding that has a fuse B. To the side of the transformer's primary winding without a fuse C. To the black wire D. To the rectifier junction 3AD 1-1.4 B Why is the retaining screw in one terminal of a light socket made of brass while the other one is silver colored? A. To prevent galvanic action B. To indicate correct wiring polarity C. To better conduct current D. To reduce skin effect 3AD 1-2.1 A How much electrical current flowing through the human body is usually fatal? A. As little as 100 milliamperes may be fatal B. Approximately 10 amperes is required to be fatal C. More than 20 amperes is needed to kill a human being D. No amount of current will harm you. Voltages of over 2000 volts are always fatal, however 3AD 1-2.2 A What is the minimum voltage considered to be dangerous to humans? A. 30 volts B. 100 volts C. 1000 volts D. 2000 volts 3AD 1-2.3 A How much electrical current flowing through the human body is usually painful? A. As little as 50 milliamperes may be painful B. Approximately 10 amperes is required to be painful C. More than 20 amperes is needed to be painful to a human being D. No amount of current will be painful. Voltages of over 2000 volts are always painful, however 3AD 1-3.1 C Where should the main power-line switch for a high voltage power supply be situated? A. Inside the cabinet, to interrupt power when the cabinet is opened B. On the rear panel of the high-voltage supply C. Where it can be seen and reached easily D. This supply should not be switch-operated 3AD 2-1.1 B How is a voltmeter typically connected to a circuit under test? A. In series with the circuit B. In parallel with the circuit C. In quadrature with the circuit D. In phase with the circuit 3AD 2-2.1 C How can the range of a voltmeter be extended? A. By adding resistance in series with the circuit under test B. By adding resistance in parallel with the circuit under test C. By adding resistance in series with the meter D. By adding resistance in parallel with the meter 3AD 3-1.1 A How is an ammeter typically connected to a circuit under test? A. In series with the circuit B. In parallel with the circuit C. In quadrature with the circuit D. In phase with the circuit 3AD 3-2.1 D How can the range of an ammeter be extended? A. By adding resistance in series with the circuit under test B. By adding resistance in parallel with the circuit under test C. By adding resistance in series with the meter D. By adding resistance in parallel with the meter 3AD 4.1 D What is a multimeter? A. An instrument capable of reading SWR and power B. An instrument capable of reading resistance, capacitance and inductance C. An instrument capable of reading resistance and reactance D. An instrument capable of reading voltage, current and resistance 3AD 5-1.1 A Where in the antenna transmission line should a peak-reading wattmeter be attached to determine the transmitter output power? A. At the transmitter output B. At the antenna feed point C. One-half wavelength from the antenna feed point D. One-quarter wavelength from the transmitter output 3AD 5-1.2 C For the most accurate readings of transmitter output power, where should the RF wattmeter be inserted? A. The wattmeter should be inserted and the output measured one-quarter wavelength from the antenna feed point B. The wattmeter should be inserted and the output measured one-half wavelength from the antenna feed point C. The wattmeter should be inserted and the output power measured at the transmitter antenna jack D. The wattmeter should be inserted and the output power measured at the Transmatch output 3AD 5-1.3 B At what line impedance are RF wattmeters usually designed to operate? A. 25 ohms B. 50 ohms C. 100 ohms D. 300 ohms 3AD 5-1.4 A What is a directional wattmeter? A. An instrument that measures forward or reflected power B. An instrument that measures the directional pattern of an antenna C. An instrument that measures the energy consumed by the transmitter D. An instrument that measures thermal heating in a load resistor 3AD 5-2.1 B If a directional RF wattmeter indicates 90 watts forward power and 10 watts reflected power, what is the actual transmitter output power? A. 10 watts B. 80 watts C. 90 watts D. 100 watts 3AD 5-2.2 C If a directional RF wattmeter indicates 96 watts forward power and 4 watts reflected power, what is the actual transmitter output power? A. 80 watts B. 88 watts C. 92 watts D. 100 watts 3AD 6.1 A What is a marker generator? A. A high-stability oscillator that generates a series of reference signals at known frequency intervals B. A low-stability oscillator that "sweeps" through a bend of frequencies C. An oscillator often used in aircraft to determine the craft's location relative to the inner and outer markers at airports D. A high-stability oscillator whose output frequency and amplitude can be varied over a wide range 3AD 6.2 D What type of circuit is used to inject a frequency calibration signal into a communications receiver? A. A product detector B. A receiver incremental tuning circuit C. A balanced modulator D. A crystal calibrator 3AD 6.3 A How is a marker generator used? A. To calibrate the tuning dial on a receiver B. To calibrate the volume control on a receiver C. To test the amplitude linearity of an SSB transmitter D. To test the frequency deviation of an FM transmitter 3AD 7.1 C What piece of test equipment produces a stable, low-level signal that can be set to a specific frequency? A. A wavemeter B. A reflectometer C. A signal generator D. A balanced modulator 3AD 7.2 B What is an RF signal generator commonly used for? A. Measuring RF signal amplitude B. Aligning receiver tuned circuits C. Adjusting the transmitter impedance-matching network D. Measuring transmission line impedance 3AD 8-1.1 D What is a reflectometer? A. An instrument used to measure signals reflected from the ionosphere B. An instrument used to measure radiation resistance C. An instrument used to measure transmission-line impedance D. An instrument used to measure standing wave ratio 3AD 8-1.2 D What is the device that can indicate an impedance mismatch in an antenna system? A. A field-strength meter B. A set of lecher wires C. A wavemeter D. A reflectometer 3AD 8-2.1 A For best accuracy when adjusting the impedance match between an antenna and feed line, where should the match-indicating device be inserted? A. At the antenna feed point B. At the transmitter C. At the midpoint of the feed line D. Anywhere along the feed line 3AD 8-2.2 C Where should a reflectometer be inserted into a long antenna transmission line in order to obtain the most valid standing wave ratio indication? A. At any quarter-wavelength interval along the transmission line B. At the receiver end C. At the antenna end D. At any even half-wavelength interval along the transmission line 3AD 9.1 D When adjusting a transmitter filter circuit, what device is connected to the transmitter output? A. A multimeter B. A set of Litz wires C. A receiver D. A dummy antenna 3AD 9.2 B What is a dummy antenna? A. An isotropic radiator B. A nonradiating load for a transmitter C. An antenna used as a reference for gain measurements D. The image of an antenna, located below ground 3AD 9.3 C Of what materials may a dummy antenna be made? A. A wire-wound resistor B. A diode and resistor combination C. A noninductive resistor D. A coil and capacitor combination 3AD 9.4 B What station accessory is used in place of an antenna during transmitter tests so that no signal is radiated? A. A Transmatch B. A dummy antenna C. A low-pass filter D. A decoupling resistor 3AD 9.5 A What is the purpose of a dummy load? A. To allow off-the-air transmitter testing B. To reduce output power for QRP operation C. To give comparative signal reports D. To allow Transmatch tuning without causing interference 3AD 9.6 A How many watts should a dummy load for use with a 100-watt emission J3E transmitter with 50 ohm output be able to dissipate? A. A minimum of 100 watts continuous B. A minimum of 141 watts continuous C. A minimum of 175 watts continuous D. A minimum of 200 watts continuous 3AD 10.1 C What is an S-meter? A. A meter used to measure sideband suppression B. A meter used to measure spurious emissions from a transmitter C. A meter used to measure relative signal strength in a receiver D. A meter used to measure solar flux 3AD 10.2 A A meter that is used to measure relative signal strength in a receiver is known as what? A. An S-meter B. An RST-meter C. A signal deviation meter D. An SSB meter 3AD 11-1. B Large amounts of RF energy may cause damage to body tissue, depending on the wavelength of the signal, the energy density of the RF field, and other factors. How does RF energy effect body tissue? A. It causes radiation poisonings B. It heats the tissue C. It cools the tissue D. It produces genetic changes in the tissue 3AD 11-1. A Which body organ is most susceptible to damage from the heating effects of radio frequency radiation? A. Eyes B. Hands C. Heart D. Liver 3AD 11-2. D Scientists have devoted a great deal of effort to determine safe RF exposure limits. What organization has established an RF protection guide? A. The Institute of Electrical and Electronics Engineers B. The American Radio Relay League C. The Environmental Protection Agency D. The American National Standards Institute 3AD 11-2. B What is the purpose of the ANSI RF protection guide? A. It protects you from unscrupulous radio dealers B. It sets RF exposure limits under certain circumstances C. It sets transmitter power limits D. It sets antenna height requirements 3AD 11-2. B The American National Standards Institute RF protection guide sets RF exposure limits under certain circumstances. In what frequency range is the maximum exposure level the most stringent (lowest)? A. 3 to 30 MHz B. 30 to 300 MHz C. 300 to 3000 MHz D. Above 1.5 GHz 3AD 11-2. D The American National Standards Institute RF protection guide sets RF exposure limits under certain circumstances. Why is the maximum exposure level the most stringent (lowest) in the ranges between 30 MHz and 300 MHz? A. There are fewer transmitters operating in this frequency range B. There are more transmitters operating in this frequency range C. Most transmissions in this frequency range are for an extended time D. Human body lengths are close to whole-body resonance in that range 3AD 11-2. B The American National Standards Institute RF protection guide sets RF exposure limits under certain circumstances. What is the maximum safe power output to the antenna terminal of a hand-held VHF or UHF radio, as set by this RF protection guide? A. 125 milliwatts B. 7 watts C. 10 watts D. 25 watts 3AD 11-3. C After you make internal tuning adjustments to your VHF power amplifier, what should you do before you turn the amplifier on? A. Remove all amplifier shielding to ensure maximum cooling B. Connect a noise bridge to eliminate any interference C. Be certain all amplifier shielding is fastened in place D. Be certain no antenna is attached so that you will not cause any interference -------------------------------------------------- End of Subelement 3AD.