A) 0.5 and 9 kHz
B) 0.5 and 10 kHz
C) 0.3 and 9 kHz
D) 0.4 and 10 kHz
Correct Answer: A
Solution :
[a] Modulation index is given by \[m=\frac{{{\Alpha }_{m}}}{{{\Alpha }_{c}}}=\frac{2}{4}=0.5\] & carrier wave frequency is given by \[=2\pi {{f}_{c}}=2\times {{10}^{4}}\pi \] \[{{f}_{c}}=10\,kHz\] [b] modulating wave frequency \[({{f}_{m}})\] \[2\pi {{f}_{m}}=2000\pi \]\[\Rightarrow {{f}_{m}}=1\,kHz\] lower side band frequency \[\Rightarrow {{f}_{c}}-{{f}_{m}}\] \[\Rightarrow 10\,kHz-1\,kHz=9\,kHz\] Modulation index is given by \[m=\frac{{{\Alpha }_{m}}}{{{\Alpha }_{c}}}=\frac{2}{4}=0.5\] & carrier wave frequency is given by \[=2\pi {{f}_{c}}=2\times {{10}^{4}}\pi \] \[{{f}_{c}}=10\,kHz\] [b] modulating wave frequency \[({{f}_{m}})\] \[2\pi {{f}_{m}}=2000\pi \]\[\Rightarrow {{f}_{m}}=1\,kHz\] lower side band frequency \[\Rightarrow {{f}_{c}}-{{f}_{m}}\] \[\Rightarrow 10\,kHz-1\,kHz=9\,kHz\]You need to login to perform this action.
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