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Question 1

Describe Amplitude Modulation

Answer 1

• A way of transmission that allows waves to travel further distances
• The wave produced by a voice is modulated onto a carrier wave
• As the signal wave’s amplitude increases, the amplitude of the modulated wave increases. Frequency stays the same
• When being received, the radio wave is passed through a demodulator which removes the carrier frequency waves while the signal remains

Question 2

Describe Frequency Modulation

Answer 2

• Modulates the frequency of the carrier wave and not the amplitude
• As the amplitude of the signal wave increases the frequency of the FM wave increases, while reduced signal wave = decreased frequency
• Advantages over AM : is not affected by induced noise as it affects the amplitude of the wave and for FM, the amplitude does not carry the information

Question 3

Which part of the radio receiver alters the frequency received

Answer 3

• The Coil, the number of turns determines what frequency is received.

Question 4

What part of the radio receiver receives the modulated radio wave

Answer 4

• The antenna

Question 5

How does the demodulator work inside the radio receiver

Answer 5

• Since the modulated signal is a sine wave, a diode can cut off the negative half of it, which leaves behind a RECTIFIED signal
• The capacitor then fills in the troughs of the wave with the original source wave that was modulated onto the carrier wave