The FM transmission of music is of very good quality in comparison to AM transmission. Consider the following statements with this reference:
1. The AM signals are more susceptible to noise
2. The FM receiver locks itself to catch stronger signal only
3. The wavelength of AM waves is much higher in comparison to the FM waves
Which among the above is / are correct statements:
The first statement is correct. Signal quality is a lot superior in FM than AM because the amplitude based signals are more susceptible to noise than those which use frequency. Further, the noise signals are difficult to filter out in AM reception whereas FM receivers easily filter out noise using the capture effect and pre-emphasis, de-emphasis effects. In capture effect, the receiver locks itself to catch stronger signal so that signals received are more synced with that at the transmitting end.
In pre-emphasis, de-emphasis process, the signal is further amplified to a higher frequency at sending end (pre-emphasis) and vice versa at receiver end (de-emphasis). These two processes reduce down the chances of a signal to get mixed with other signals and make FM more immune to noise than AM.
The third statement is also correct. AM waves work in the range of KHz while in FM waves work in MHz range. As a result, AM waves have a higher wavelength than the FM ones. A higher wavelength increases the range of AM signals as compared to FM which have a limited area of coverage.
This question is a part of GKToday's Integrated IAS General Studies Module