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.
Write the functions of the following in communication systems:
Transmitter
Write the functions of the following in communication systems:
Modulator
Write the functions of the following in communication systems:
Receiver
Write the functions of the following in communication systems:
Demodulator
Explain the term demodulation used in a communication system.
Distinguish between broadcast mode and point-to-point mode of communication and give one example for each.
A device X used in communication system can convert one form of energy into another. Name the device X. Explain the function of a repeater in a communication system.
Write the function of receiver in communication system.
Write the functions of the transducer and repeaters.
What is the function of a bandpass filter used in a modulator for obtaining AM signal?
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:
Which of the following would produce analog signals and which would produce digital signals?
- A vibrating tuning fork.
- Musical sound due to a vibrating sitar string.
- Light pulse.
- Output of NAND gate.
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.
