FCC T3B - 无线电波特性与电波传播

#T3B01🔗

What is the relationship between the electric and magnetic fields of an electromagnetic wave?

电磁波的电场和磁场之间有什么关系？

They travel at different speeds

他们以不同的速度行进

They are in parallel

它们是平行的

They revolve in opposite directions

它们朝相反的方向旋转

They are at right angles

它们成直角

✓ 正确答案

#T3B02🔗

What property of a radio wave defines its polarization?

无线电波的什么特性决定了它的极化？

The orientation of the electric field

电场方向

✓ 正确答案

The orientation of the magnetic field

磁场方向

The ratio of the energy in the magnetic field to the energy in the electric field

磁场中的能量与电场中的能量之比

The ratio of the velocity to the wavelength

速度与波长之比

#T3B03🔗

What are the two components of a radio wave?

无线电波的两个组成部分是什么？

Impedance and reactance

阻抗和电抗

Voltage and current

电压和电流

Electric and magnetic fields

电场和磁场 _

✓ 正确答案

Ionizing and non-ionizing radiation

电离和非电离辐射

#T3B04🔗

What is the velocity of a radio wave traveling through free space?

无线电波穿过自由空间的速度是多少？

Speed of light

光速_

✓ 正确答案

Speed of sound

声音的速度

0.86 times the speed of light

0.86倍光速

1.86 times the speed of sound

1.86倍音速

#T3B05🔗

What is the relationship between wavelength and frequency?

波长和频率有什么关系？

Wavelength gets longer as frequency increases

波长随着频率的增加而变长

Wavelength gets shorter as frequency increases

波长随着频率的增加而变短

✓ 正确答案

Wavelength is constant at all frequencies

波长在所有频率下都是恒定的

Wavelength and frequency increase as path length increases

波长和频率随着路径长度的增加而增加

#T3B06🔗

What is the formula for converting frequency to approximate wavelength in meters?

将频率转换为以米为单位的近似波长的公式是什么？

Wavelength in meters equals frequency in hertz multiplied by 300

以米为单位的波长等于以赫兹为单位的频率乘以 300

Wavelength in meters equals frequency in hertz divided by 300

以米为单位的波长等于以赫兹为单位的频率除以 300

Wavelength in meters equals frequency in megahertz divided by 300

以米为单位的波长等于以兆赫兹为单位的频率除以 300

Wavelength in meters equals 300 divided by frequency in megahertz

以米为单位的波长等于 300 除以以兆赫为单位的频率

✓ 正确答案

#T3B07🔗

In addition to frequency, which of the following is used to identify amateur radio bands?

除了频率之外，以下哪项用于识别业余无线电频段？

The approximate wavelength in meters

以米为单位的近似波长

✓ 正确答案

Traditional letter/number designators

传统的字母/数字指示符

Channel numbers

频道号码

All these choices are correct

这些选项都是正确的

#T3B08🔗

What frequency range is referred to as VHF?

什么频率范围称为 VHF？

30 kHz to 300 kHz

30 kHz 至 300 kHz

30 MHz to 300 MHz

30 兆赫至 300 兆赫

✓ 正确答案

300 kHz to 3000 kHz

300 kHz 至 3000 kHz

300 MHz to 3000 MHz

300 兆赫至 3000 兆赫

#T3B09🔗

What frequency range is referred to as UHF?

什么频率范围称为UHF？

30 to 300 kHz

30 至 300 kHz

30 to 300 MHz

30 至 300 兆赫

300 to 3000 kHz

300 至 3000 kHz

300 to 3000 MHz

300 至 3000 兆赫

✓ 正确答案

#T3B10🔗

What frequency range is referred to as HF?

什么频率范围称为HF？

300 to 3000 MHz

300 至 3000 兆赫

30 to 300 MHz

30 至 300 兆赫

3 to 30 MHz

3至 30 兆赫

✓ 正确答案

300 to 3000 kHz

300 至 3000 kHz

#T3B11🔗

What is the approximate velocity of a radio wave in free space?

无线电波在自由空间中的近似速度是多少？

150,000,000 meters per second

每秒 150,000,000 米

300,000,000 meters per second

每秒 300,000,000 米

✓ 正确答案

300,000,000 miles per hour

每小时 300,000,000 英里

150,000,000 miles per hour

每小时 150,000,000 英里

#T3B12🔗

Which of these frequencies travels at the highest velocity in free space?

以下哪个频率在自由空间中以最高速度传播？

Microwaves

微波炉

UHF

超高频

VHF

甚高频

All radio frequencies travel at the same velocity

所有无线电频率以相同的速度传播

✓ 正确答案

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FCC T3B - 无线电波特性与电波传播

小节 T3B：无线电波特性与电波传播