FCC T0A - 电气与射频安全

#T0A01🔗

Which of the following is a safety hazard of a 12-volt storage battery that lacks internal protection circuitry?

以下哪项是缺乏内部保护电路的12伏蓄电池的安全隐患？

Touching both terminals with your hands can cause electrical shock

用手触摸两个端子可能会导致触电

Shorting the terminals can cause burns , fire, or an explosion

短路端子会导致燃烧、火灾或爆炸

✓ 正确答案

RF emissions from a nearby transmitter can cause the electrolyte to emit poison gas

附近发射器的射频辐射会导致电解液释放有毒气体

All these choices are correct

这些选项都是正确的

#T0A02🔗

What health hazard is posed by electrical current flowing through the body?

电流流过人体会对健康造成哪些危害？

It may cause injury by heating body tissue

它可能会因加热身体组织而造成伤害

It may disrupt the electrical functions of cells

它可能会破坏细胞的电功能

It may cause involuntary muscle contractions

它可能会导致不自主的肌肉收缩

All these choices are correct

这些选项都是正确的

✓ 正确答案

#T0A03🔗

In the United States, what circuit does black wire insulation indicate in a three-wire 120 V AC cable?

在美国，三线 120 V 交流电缆中的黑线绝缘表示什么电路？

Neutral

中性的

Hot

火线

✓ 正确答案

Equipment ground

设备地

Negative

阴性

#T0A04🔗

What is the purpose of a fuse in an electrical circuit?

保险丝在电路中的作用是什么？

To prevent power supply ripple from damaging a component

防止电源纹波损坏元器件

To remove power in case of an overload

过载时切断电源

✓ 正确答案

To limit current and prevent shocks

限制电流并防止电击

All these choices are correct

这些选项都是正确的

#T0A05🔗

Why should a 5-ampere fuse never be replaced with a 20-ampere fuse?

为什么不能用 20 安培的保险丝代替 5 安培的保险丝？

The larger fuse would be likely to blow because it is rated for higher current

较大的保险丝可能会熔断，因为它的额定电流较高

The power supply ripple would greatly increase

电源纹波会大大增加

Excessive current could cause a fire

电流过大可能会引起火灾

✓ 正确答案

Voltage drop in the higher current fuse could result in excessively low voltage to the device

高电流保险丝中的电压降可能会导致设备电压过低

#T0A06🔗

What is a good way to guard against electrical shock at your station?

在您的工作台上防止触电的好方法是什么？

Use three-wire cords and plugs for all AC powered equipment

对所有交流供电设备使用三芯线和插头

Connect all AC powered station equipment to a common safety ground

将所有交流供电站设备连接到一个共同的安全接地点

Ensure all capacitors used for high-voltage DC are fully discharged before working inside equipment

在设备内部工作之前，确保所有用于高压直流的电容器已完全放电

All these choices are correct

这些选项都是正确的

✓ 正确答案

#T0A07🔗

Where should a lightning arrester be installed in a coaxial feed line?

避雷器应该安装在同轴馈线的什么位置？

At the output connector of a transceiver

在收发器的输出连接器

At the antenna feed point

在天线馈电点

At the AC power service panel

在交流电源服务面板

On a grounded panel near where feed lines enter the building

在进线进入建筑物附近的接地面板上

✓ 正确答案

#T0A08🔗

Where should a fuse or circuit breaker be installed in a 120V AC power circuit?

120V交流电源电路中，熔断器或断路器应安装在什么位置？

In series with the hot conductor only

仅与热导体串联

✓ 正确答案

In series with the hot and neutral conductors

与火线和中性线串联

In parallel with the hot conductor only

仅与热导体并联

In parallel with the hot and neutral conductors

与火线和中性线并联

#T0A09🔗

What should be done to all external ground rods or earth connections?

应该如何处理所有外部接地棒或接地连接？

Waterproof them with silicone caulk or electrical tape

用硅胶填缝剂或电工胶带防水

Keep them as far apart as possible

让他们尽可能远离

Bond them together with heavy wire or conductive strap

用粗线或导电带将它们粘合在一起

✓ 正确答案

Tune them for resonance on the lowest frequency of operation

调整它们以在最低工作频率上产生共振

#T0A10🔗

What hazard exists when rapidly charging or discharging an unprotected battery?

对未受保护的电池快速充电或放电时存在什么危险？

Overheating or out- gassing

过热或放气

✓ 正确答案

Excess output ripple

过大的输出纹波

Electric shock

触电

Overvoltage

过电压

#T0A11🔗

What hazard exists in a power supply immediately after turning it off?

电源刚关掉有什么危害？

Circulating currents in the dc filter

直流滤波器中的循环电流

Leakage flux in the power transformer

电源变压器中的漏磁通

Voltage transients from kickback diodes

来自反冲二极管的电压瞬变

Charge stored in filter capacitors

存储在滤波电容器中的电荷

✓ 正确答案

#T0A12🔗

Which of the following precautions should be taken when measuring high voltages with a voltmeter?

用电压表测量高压时应注意下列哪项？

Ensure that the voltmeter has very low impedance

确保电压表具有非常低的阻抗

Ensure that the voltmeter and its leads are rated for use at the voltages being measured

确保电压表及其引线适合在测量电压下使用

✓ 正确答案

Ensure that the circuit is grounded through the voltmeter

确保电路通过电压表接地

Ensure that the voltmeter is set to the correct frequency

确保电压表设置为正确的频率

← 上一节: T9B 📑 返回 T0 大纲下一节: T0B →

FCC T0A - 电气与射频安全

小节 T0A：电气与射频安全