Please solve question 30 and 33. Section 3.3 30, An audio system requires a freq
ID: 2292965 • Letter: P
Question
Please solve question 30 and 33.
Section 3.3 30, An audio system requires a frequency response from 50 Hz to 15 kHz for high fidelity. If this signal were transmitte using AM, what bandwidth would it require? 31. A transmitter operates with a carrier frequency of 7.2 MHz. It is amplitude-modulated by two tones with frequencies of 1500 and 3000 Hz, What frequencies are produced at its output? 32. Sketch the signal whose equation is given in problem 24, in the frequency domain, showing frequency and voltage scales. 33. An AM signal has the following characteristics: f 150 MHz fn 3 kHz E 40 V E 50 V For this signal, find: (a) the modulation index (b) the bandwidth (c) the peak voltage of the upper side frequencyExplanation / Answer
30 ) Bandwidth = 2 * Fm
= 2*15KHz = 30 KHz
33 ) (a) Modulation index = Em /Ec
=40/50 = 0.8 (No unit)
(b) Bandwidth = 2 * Fm
= 2* 3KHz = 6KHz
(c) Peak voltage of the upper side frequency Vp= Vc + Vm
=Ec /2 + Em /2
= 50/2 +40/2
= + 45V