Question
Physics Question on Electromagnetic waves
A sinusoidal wave y(t) = 40sin(10 × 106 π t) is amplitude modulated by another sinusoidal wave x(t) = 20sin(1000π t). The amplitude of minimum frequency component of modulated signal is:
A
0.5
B
0.25
C
20
D
10
Answer
10
Explanation
Solution
The correct answer is (D): 10
Explanation:
Modulate signal s(t) ≡ [1 + 20sin(1000π t)] sin(107π t)
≡ sin(107π t) + 10cos(107π t – 103π t) + 10cos(107π t + 103π t)
⇒ Required amplitude = 10