Correct Answer - Option 2 : 8 W
Calculation:
Given frequency band from 10 Hz to 20 Hz.
A sinusoidal signal is represented as,
v = Vm sin (2πft + θ)
Where,
Vm is the amplitude
Considerd the signal,
X(t) = X1(t) + X2(t) = 10 cos (10πt + π/7) + 4 sin (30πt + π/8)
X1(t) = 10 cos (10πt + π/7)
2πft = 10πt
f = 5 Hz
Hence, X1(t) frequency not lies between the frequency band 10 Hz to 20 Hz.
X2(t) = 4 sin (30πt + π/8)
2πft = 30πt
f = 15 Hz
Hence, X2(t) frequency lies between the frequency band 10 Hz to 20 Hz.
Power laying (P) of the signal is given as,
\({P} = \frac{{A^2}}{2}\)
Where A is the amplitude
For signal X2(t),
A = 4
\({P} = \frac{{4^2}}{2}=8 W\)
