WorksheetsSurprise Quiz - I
Total questions: 10
Worksheet time: 10mins
The purpose of carrier modulation is to
reduce the message amplitude for better radiation
shift the message to higher frequency band for better radiation
increase the message amplitude for better radiation
shift the message to lower frequency band for better radiation
An AM transmitter radiates 500kW. If the modulation Index is 0.5, calculate the carrier power.
100kW
562.5kW
444.44 kW
101.25kW
The ability of receivers to select the wanted signals among various incoming signal is called ________.
Selectivity
Fidelity
Sensitivity
Modulation
The maximum power efficiency of an AM modulator is _________.
25%
33%
66%
100%
If the message signal has a bandwidth of W Hz, bandwidth of DSBSC signal is
W
2W
W/2
W+fv
A carrier is simultaneously modulated by two sine waves with modulation indices of 0.4 and 0.3 .The resultant modulation index will be_________.
1
0.7
0.5
0.35
Sensitivity is defined as ___________
ability to reject unwanted signals
ability of the receiver to amplify weak signals
ability to reject noise
ability to convert incoming signal into IF
In AM, for 100% modulation, power in each sideband is ________ of that of carrier.
50%
70%
60%
25%
The modulation index in AM is changed from 0 to 1 .The transmitted power ______.
increases by 50%
increases by 100%
increases by 75%
remains unaffected
An AM signal is represented by s(t) = 30cos(20000π t) + 20cos(700πt).cos(20000πt). What is the unmodulated carrier power in watts for unit load resistance?
555
675
450
310
