When a sinusoidal message signal is applied to the X-plates of a CRO and the corresponding amplitude modulated (AM) signal is applied to the y-plates, the X-Y plot displayed on the screen of the CRO is as shown in the figure below.

The modulation index of the AM signal is equal to _____.
1.67

Open in App

Solution

The correct option is A 1.67
The axis crossing in the given X - Y plot indicates the phase reversal of the AM signal at zero crossings, which occurs in case of over-modulation.

$So, modulation index, μ = \frac{4 - (- 1)}{4 + (- 1)} = \frac{5}{3} = 1.67$

Suggest Corrections

Similar questions

When a sinusodial carrier signal is amplitude modulated by a siusodial message signal m_{1} (t), the modulation index of the resultant AM signal is 0.80. When this AM signal is simultaneously modulated by one more sinusoidal message signal m_{2} (t) the total power of the Am signal become double. The modulation index of the Am signal obtained due to m_{2} (t) alone will be_______

The periodic message signal, shown in he figure below, is applied to a modulator to modulate the amplitude of a sinusodial carrier signal. If the amplitude sensitivity of the modulator is 0.25 V^{- 1}, then the transmission efficiency achieved by the resultant modulated signal will be

Join BYJU'S Learning Program