Question

A signal wave of frequency $ 12\, kHZ $ is modulated with a carrier wave of frequency $ 2.51\, MHz $ . The upper and lower side band frequencies are respectively

• A. $2512\, kHz$ and $2508 \,kHz$
• B. $2522\, kHz$ and $2488\, kHz$
• C. $2502\, kHz$ and $2498\, kHz$
• D. $2522\, kHz$ and $2498\, kHz$
• E. $2512\, kHz$ and $2488\, kHz$

Answer 1

Answer: (D)

Upper side band (USB) frequency
$ ={{f}_{c}}+{{f}_{m}} $ $ =(2.51)\text{ }MHz+(12)\text{ }kHz $
$ =(2510+12)\text{ }kHz $ $ =2522\text{ }kHz $
Lower side band (LSB) frequency $ ={{f}_{c}}-{{f}_{m}} $
$ =(2.51)\text{ }MHz-(12)\text{ }kHz $
$ =(2510-12)\text{ }kHz $
$ =2498\text{ }kHz $