Question

In an AM wave, the information is contained within

• A. r.f. carrier wave
• B. only lower and upper side frequencies
• C. both r.f. carrier and side frequencies
• D. none of these

Answer 1

Answer: (B)

only lower and upper side frequencies

Answer 2

The modulated voltage comprises of (i) Carrier wave of frequency, $\omega_{ c }$ (ii) Lower side frequency, $\left(\omega_{ c }-\omega_{ m }\right)$ wave (iii) Upper side frequency, $\left(\omega_{ c }+\omega_{ m }\right)$ wave Thus, in an AM wave information is contained in lower $\left(\omega_{c}-\omega_{m}\right)$ and upper $\left(\omega_{c}+\omega_{m}\right)$ side frequencies.