Question

Maximum peak to peak voltage of an AM wave is $24mv$ and the minimum peak to peak voltage is $8mv$.Modulation factor is ?

Answer 1

Modulation factor is the ratio of the change of amplitude in carrier wave after modulation to the amplitude of the unmodulated carrier wave. Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio carrier wave. In amplitude modulation, the amplitude (signal strength) of the carrier wave is varied in proportion to that of the message signal, such as an audio signal.

Formula Used:
$\dfrac{{{V_{\max }} - {V_{\min }}}}{{{V_{\max }} + {V_{\min }}}}$
Here ${V_max}$ and ${V_min}$ are the maximum and minimum voltages respectively.

Complete step by step answer:
In this question, maximum voltage and the minimum peak voltage is given,
Maximum voltage ${V_{\max }}$ = $\dfrac{{24}}{2}$= $12mV$
Minimum voltage ${V_{\min }}$ = $\dfrac{8}{2}$= $4mV$
We know, Modulation factor = $\dfrac{{{V_{\max }} - {V_{\min }}}}{{{V_{\max }} + {V_{\min }}}}$
Now, substitute the value of minimum and maximum voltage in the formula of modulation factor, we get-
$\Rightarrow\dfrac{{12 - 4}}{{12 + 4}}$ = $\dfrac{8}{{16}}$ = 0.5

So, the value of modulation factor is $0.5$.

Note: The ratio of the peak variation in the modulation actually used in a transmitter to the maximum variation for which the transmitter was designed. Also the peak to peak is the measure of the total length variation of the waveform in positive and negative y-axis whereas the maximum voltage is the length from the original axis.