Quiz on Frequency modulation

According to Carson’s rule, Bandwidth B and modulating frequency fm are related as

(a)  

What is the maximum frequency deviation allowed in commercial FM broadcasting?

• 100 KHz

• 75 KHz

• 150 KHz

• 20 KHz

In Frequency Modulation –

• Amplitude of the carrier remains same

• Frequency of the carrier varies in accordance with the modulating signal

• The number of side bands are infinite

• Amplitude of the carrier varies in accordance with the modulating signal

State carson's rule

In radio receivers, varactor diodes are used for

• Tuning

• Demodulation

• Mixing

• None of the above

Pre emphasis is done

• For boosting of modulating signal voltage

• For modulating signals at higher frequencies

• In FM before modulation

• All of the above

Armstrong method is used for the generation of

(a)  

Disadvantages of FM over AM are

• Prone to selective fading

• Capture Effect

• Poorer signal to noise ratio at high audio frequencies

• Low bandwidth