Advertisements
Advertisements
Question
Audio sine waves of 3 kHz frequency are used to amplitude modulate a carrier signal of 1.5 MHz. Which of the following statements are true?
- The sideband frequencies are 1506 kHz and 1494 kHz.
- The bandwidth required for amplitude modulation is 6 kHz.
- The bandwidth required for amplitude modulation is 3 MHz.
- The side band frequencies are 1503 kHz and 1497 kHz.
Options
a and b
b and d
c and a
b and c
Advertisements
Solution
b and d
Explanation:
LSB = `(ω_c) = (ω_m)`
= `1.5 xx 10^6 - 3 xx 10^3`
= 1497 kHz
And USB = `(ω_c) + (ω_m)`
= 1503 kHz
Bandwidth required = USB – LSB = `2ω_m`
= `2 xx 3 kHz`
= 6 kHz
Also,bandwidth = 2fm = 2 × 3 = 6 KHz
APPEARS IN
RELATED QUESTIONS
Explain the terms Attenuation used in Communication System.
Explain the terms : Transmitter in communication system
What is the function of a 'Repeater' used in communication system?
Write the functions of the following in communication systems:
Modulator
Write the functions of the following in communication systems:
Transducer
Write the functions of the following in communication systems:
Receiver
Write the functions of the following in communication systems:
Demodulator
Distinguish between broadcast mode and point-to-point mode of communication and give one example for each.
Distinguish between point to point and broadcast modes of communication. Give an example of each.
Explain the basic concept of mobile telephoning ?
Distinguish between point to point and broadcast modes of communication. Give an example of each.
Write the function of receiver in communication system.
A 1 KW signal is transmitted using a communication channel which provides attenuation at the rate of – 2dB per km. If the communication channel has a total length of 5 km, the power of the signal received is `["gain in dB" = 10 log ("P"_0/"P"_"i")]`
A basic communication system consists of ______.
- transmitter.
- information source.
- user of information.
- channel.
- receiver.
Choose the correct sequence in which these are arranged in a basic communication system:
Figure shows a communication system. What is the output power when input signal is of 1.01 mW? (gain in dB = 10 log10 (Po/Pi).
An audio signal is modulated by a carrier wave of 20 MHz such that the bandwidth required for modulation is 3 kHz. Could this wave be demodulated by a diode detector which has the values of R and C as
- R = 1 kΩ, C = 0.01 µF.
- R = 10 kΩ, C = 0.01 µF.
- R = 10 kΩ, C = 0.1 µF.
