An amplitude modulated signal is plotted below: Which one of the...

An amplitude modulated signal is plotted below:

Which one of the following best describes the above signal?

Options

A $\left(9+\sin \left(2.5 \pi \times 10^{5} \mathrm{t}\right)\right) \sin \left(2 \pi \times 10^{4} \mathrm{t}\right) \mathrm{V}$
B $\left(1+9 \sin \left(2 \pi \times 10^{4} \mathrm{t}\right)\right) \sin \left(2.5 \pi \times 10^{5} \mathrm{t}\right) \mathrm{V}$
C $\left(9+\sin \left(2 \pi \times 10^{4} t\right)\right) \sin \left(2.5 \pi \times 10^{5} \mathrm{t}\right) \mathrm{V}$
D $\left(9+\sin \left(4 \pi \times 10^{4} t\right)\right) \sin \left(5 \pi \times 10^{5} \mathrm{t}\right) \mathrm{V}$

C. $\left(9+\sin \left(2 \pi \times 10^{4} t\right)\right) \sin \left(2.5 \pi \times 10^{5} \mathrm{t}\right) \mathrm{V}$

After analysing the graph we may conclude that (i) Amplitude varies as

8-10 \mathrm{~V}

9 \pm 1

(ii) Two time period as

100 \mu

s (signal wave)

\& 8 \mu

(carrier wave) So, equation of AM signal is

\left[9 \pm 1 \sin \left(\frac{2 \pi t}{T_{1}}\right) \sin \left(\frac{2 \pi t}{T_{2}}\right)\right] =\left[9 \pm \sin \left(2 \pi \times 10^{4} \mathrm{t}\right)\right] \sin \left(2.5 \pi \times 10^{5} \mathrm{t}\right) \mathrm{V}