Why amplitude modulation is used for broadcasting

The questions posted on the site are solely user generated, Doubtnut has no ownership or control over the nature and content of those questions. Doubtnut is not responsible for any discrepancies concerning the duplicity of content over those questions. Study Materials. Why use Doubtnut?

Instant Video Solutions. Request OTP. Question : AM is used for broadcasting because a it is more noise immune than other modulation systems b it requires less transmitting power compared with other systems c its use avoids receiver complexity d no other modulation system can provide the necessary bandwidth. Although one of the earliest used forms of modulation it is still used today, mainly for long, medium and short wave broadcasting and for some aeronautical point to point communications.

One of the key reasons for the use of amplitude modulation was its ease of use. The system simply required the carrier amplitude to be modulated, but more usefully the detector required in the receiver could be a simple diode based circuit. This meant that AM radios did not need complicated demodulators and costs were reduced - a key requirement for widespread use of radio technology, especially in the early days of radio when ICs were not available.

The first amplitude modulated signal was transmitted in by a Canadian engineer named Reginald Fessenden. He took a continuous spark transmission and placed a carbon microphone in the antenna lead. The sound waves impacting on the microphone varied its resistance and in turn this varied the intensity of the transmission. Although very crude, signals were audible over a distance of a few hundred metres, although there was a rasping sound caused by the spark. With the introduction of continuous sine wave signals, transmissions improved significantly, and AM soon became the standard for voice transmissions.

Nowadays, amplitude modulation, AM is used for audio broadcasting on the long medium and short wave bands, and for two way radio communication at VHF for aircraft. However as there now are more efficient and convenient methods of modulating a signal, its use is declining, although it will still be very many years before it is no longer used.

Amplitude modulation is used in a variety of applications. Even though it is not as widely used as it was in previous years in its basic format it can nevertheless still be found.

These form some of the main uses of amplitude modulation. Attempt Online. It is more noise immune than other modulation systems Compared with other systems it requires less transmitting power Its use avoids receiver complexity No other modulation system can provide the necessary BW for high fidelity.

Start Now. Advantage of AM: The advantages of AM radio are that it is relatively easy to detect with simple equipment, even if the signal is not very strong. It has a narrower bandwidth than FM, and wider coverage compared with FM radio.

Its use avoids receiver complexity, thus reducing the cost at the receiver end. This makes them suitable for broadcasting purposes. Disadvantages of AM: In AM most of the transmitted power is in a carrier that contains no information. It is affected by noise. In AM if there are two more signals received at the same frequency, then both will be demodulated which can lead to interference.

In FM, the message is stored in the form of variation in frequency so it has better noise immunity. Bandwidth B. Only a diode and a capacitor are sufficient to separate the audio signal from the AM wave. Questions from Communication Systems. Principle on which an optical fibre work is. The purpose of modulating a signal in transmission is. A discontinuous signal signal value which appears in steps in predetermined levels is called.

Analog signal can be converted into digital signal and vice-versa with the help of a device called. Amplitude modulation has KCET