Technician 6月 4 2024 SUBELEMENT T0A SUBELEMENT T0A T0A – Power circuits and hazards: hazardous voltages, fuses and circuit breakers, grounding, electrical code compliance; Lightning protection; Battery safety 1 / 12 T0A01Which of the following is a safety hazard of a 12-volt storage battery? A. Touching both terminals with the hands can cause electrical shock B. Shorting the terminals can cause burns, fire, or an explosion C. RF emissions from a nearby transmitter can cause the electrolyte to emit poison gas D. All these choices are correct 2 / 12 T0A02What health hazard is presented by electrical current flowing through the body? A. It may cause injury by heating tissue B. It may disrupt the electrical functions of cells C. It may cause involuntary muscle contractions D. All these choices are correct 3 / 12 T0A03In the United States, what circuit does black wire insulation indicate in a three-wire 120 V cable? A. Neutral B. Hot C. Equipment ground D. Black insulation is never used 4 / 12 T0A04What is the purpose of a fuse in an electrical circuit? A. To prevent power supply ripple from damaging a component B. To remove power in case of overload C. To limit current to prevent shocks D. All these choices are correct 5 / 12 T0A05Why should a 5-ampere fuse never be replaced with a 20-ampere fuse? A. The larger fuse would be likely to blow because it is rated for higher current B. The power supply ripple would greatly increase C. Excessive current could cause a fire D. All these choices are correct 6 / 12 T0A06What is a good way to guard against electrical shock at your station? A. Use three-wire cords and plugs for all AC powered equipment B. Connect all AC powered station equipment to a common safety ground C. Install mechanical interlocks in high-voltage circuits D. All these choices are correct 7 / 12 T0A07Where should a lightning arrester be installed in a coaxial feed line? A. At the output connector of a transceiver B. At the antenna feed point C. At the ac power service panel D. On a grounded panel near where feed lines enter the building 8 / 12 T0A08Where should a fuse or circuit breaker be installed in a 120V AC power circuit? A. In series with the hot conductor only B. In series with the hot and neutral conductors C. In parallel with the hot conductor only D. In parallel with the hot and neutral conductors 9 / 12 T0A09What should be done to all external ground rods or earth connections? A. Waterproof them with silicone caulk or electrical tape B. Keep them as far apart as possible C. Bond them together with heavy wire or conductive strap D. Tune them for resonance on the lowest frequency of operation 10 / 12 T0A10What hazard is caused by charging or discharging a battery too quickly? A. Overheating or out-gassing B. Excess output ripple C. Half-wave rectification D. Inverse memory effect 11 / 12 T0A11What hazard exists in a power supply immediately after turning it off? A. Circulating currents in the dc filter B. Leakage flux in the power transformer C. Voltage transients from kickback diodes D. Charge stored in filter capacitors 12 / 12 T0A12Which of the following precautions should be taken when measuring high voltages with a voltmeter? A. Ensure that the voltmeter has very low impedance B. Ensure that the voltmeter and leads are rated for use at the voltages to be measured C. Ensure that the circuit is grounded through the voltmeter D. Ensure that the voltmeter is set to the correct frequency Your score isThe average score is 50% 0% Restart quiz Ed 0 コメント
