Comunicações I - 3 Electromagnetic Waves

What is a radio signal?

• A type of mechanical wave

• A type of thermal wave

• A type of electromagnetic wave

• A type of sound wave

What unit is frequency measured in?

• Joules

• Watts

• Hertz

• Meters

What happens to wavelength as frequency increases?

• Wavelength becomes unpredictable

• Wavelength decreases

• Wavelength remains the same

• Wavelength increases

Which of the following is a characteristic of electromagnetic waves?

• Absorption

• Convection

• Conduction

• Reflection

What is refraction?

• Reflection of waves off a surface

• Bending of waves in a vacuum

• Bending of waves as they pass through different media

• Spreading of waves through an aperture

What does diffraction refer to?

• The cancellation of waves

• The absorption of waves

• The spreading of waves

• The bending of waves

What is the role of the ionosphere in radio communication?

• It amplifies radio waves

• It generates radio waves

• It reflects radio waves

• It absorbs radio waves

Which frequency range is associated with Very High Frequency (VHF)?

• 3 kHz - 30 kHz

• 30 MHz - 300 MHz

• 300 MHz - 3 GHz

• 30 GHz - 300 GHz

What is scattering in the context of electromagnetic waves?

• The absorption of waves

• The deflection of waves by particles

• The generation of waves

• The reflection of waves

What type of wave is primarily used in AM radio broadcasting?

• Microwave waves

• Surface waves

• Sky waves

• Space waves