EM Waves Uses and Effects

In radio communication, sound waves are fed to the radio station microphone and heard through a radio. What do you consider a radio station?

• Receiver

• Transmitter- Receiver

• Transmitter

• Radio communication

What is the function of the loudspeaker in radio communication?

• converts electrical signals to sound waves

• converts sound waves to electrical signals

• increases the intensity of the sound

• selects the frequency received

In radio communication, for sound to be transmitted and received, the following processes are involved. Arrange the processes in correct order.

I. Amplification

II. Modulation

III. Reception

IV. Demodulation

• I, II, III, IV

• II, I, IV, III

• II, I, IV, III

• III, I, II, IV

Why is it that in order for the sound waves to be transmitted and received, they should combine with the carrier waves or radio waves?

• Because radio waves can travel in space

• Because radio waves can travel over a long distance in a short time.

• Because sound signals cannot travel over a long distance in a short time

• Because sound signals can travel over a long distance in a long time.

What is the function of a broadcast antenna?

• it allows a radio transmitter to send energy into space

• It allows a receiver to pick up energy from space

• It combines the electrical signals and the carrier waves

• It separates the electrical signals from the carrier waves.

Which of the following are the components of a transmitter?

• microphone, loudspeaker, oscillator

• amplifier, demodulator, receiver antenna

• modulator, broadcast antenna, microphone

• demodulator, loudspeaker, oscillator

How does amplitude modulation differ from frequency modulation?

• The amplitude of the carrier wave is varied according to he intensity(loudness)and frequency of the source sound wave.

• The amplitude of the carrier wave is fixed and the frequency is varied according to intensity and frequency of the source sound wave.

• The frequency and amplitude of the carrier wave is fixed.

• The frequency of the carrier wave is varied according to wavelength and amplitude.

Which type of EM waves is commonly used in point to point communication system on Earth's surface and satellite communication?

• Infrared

• visible light

• microwave

• ultraviolet

Which of the following statements differentiate ionizing radiation from non-ionizing radiation?

• Non-ionizing radiation has insufficient energy to remove electrons from atoms, but ionizing radiation does not.

• Non-ionizing radiation occurs naturally and ionizing radiation is only artificially made.

• Ionizing radiation has sufficient energy to remove electrons from an atom but non-ionizing radiation does not.

• Ionizing radiation occurs naturally and non-ionizing radiation is only artificially made.

Which of the following is an example of non-ionizing radiation?

• Alpha particles

• Infrared

• Gamma rays

• X-rays