Advertisements
Advertisements
प्रश्न
What is the role of a bandpass filter?
Advertisements
उत्तर
The bandpass filter blocks the signal which is d.c. or has frequencies ω, 2ωc and 2ωm and allows a particular band of the frequency signal to pass.
APPEARS IN
संबंधित प्रश्न
The carrier wave is given by
C(t) = 2sin(8πt) volt.
The modulating signal is a square wave as shown. Find modulation index.
Due to economic reasons, only the upper sideband of an AM wave is transmitted, but at the receiving station, there is a facility for generating the carrier. Show that if a device is available which can multiply two signals, then it is possible to recover the modulating signal at the receiver station.
A carrier wave of peak voltage 15 V is used to transmit a message signal. Find the peak voltage of the modulating signal in order to have a modulation index of 60%
In a communication system, what is meant by modulation?
Define the term modulation. Draw a block diagram of a simple modulator for obtaining AM signal ?
Answer the following question.
Why a signal transmitted from a TV tower cannot be received beyond a certain distance? Write the expression for the optimum separation between the receiving and the transmitting antenna.
A 20 volt AC is applied to a circuit consisting of a resistance and a coil with negligible resistance. If the voltage across the resistance is 12 volt, the voltage across the coil is ______.
A 100 m long antenna is mounted on a 500 m tall building. The complex can become a transmission tower for waves with λ.
A speech signal of 3 kHz is used to modulate a carrier signal of frequency 1 MHz, using amplitude modulation. The frequencies of the sidebands will be ______.
I-V characteristics of four devices are shown in Figures.
 |
 |
 |
|
| (i) | (ii) | (iii) | (iv) |
Identify devices that can be used for modulation.
