Question

What modulation index and side bands are produced when a message of frequency $10 \,kHz$ and peak voltage of $10$ volts is used to modulate a carrier frequency of $1 \,MHz$ and peak voltage of 20 volts ?

• A. Modulation index is $1$ . The side bands are $1010-990\, kHz$
• B. Modulation index is $0.5$ . The side bands are $1010-990 \,kHz$
• C. Modulation index is $2$ . The side bands are $1020-980 \,kHz$
• D. Modulation index is $0.5$ . The side bands are $1020 - 980 \,kHz$

Answer 1

Answer: (B)

Modulation index is $0.5$ . The side bands are $1010-990 \,kHz$

Answer 2

Modulation Index $=\frac{10}{20}=0.5$
Sides bands are at $(1000+10\,KHz)$
$=1010\,kHz$
and $(1000-10\,KHz)$
$=990\, KHz$