Question
A modulating signal is a square wave, as shown in Fig.

The carrier wave is given by c(t) = 2sin (8$\pi$t) volts.

  1. Sketch the amplitude modulated waveform,
  2. What is the modulation index?

Answer

  1. The amplitude modulated waveform is given by superimposition of modulating signal on carrier wave and is shown below:

  1. We have,

Am = 1V, Ac = 2V.

Therefore, modulation index is given by,

$\mu=\frac{\text{A}_{\text{m}}}{\text{V}_\text{C}}=\frac{1}{2}=0.5$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Write Fleming's left hand rule.
In half-wave rectification, what is the output frequency if the input frequency is 50 Hz. What is the output frequency of a full-wave rectifier for the same input frequency?
A carrier wave of peak voltage 15 V is used to transmit a message signal. Find the peak voltage of the modulating signal in order to have a modulation of 60%.
State the research done by scientists on electromagnetism after Oersted's observation.
A current carrying loop consists of 3 identical quarter circles of radius R, lying in the positive quadrants of the x-y, y-z and z-x planes with their centres at the origin, joined together. Find the direction and magnitude of B at the origin.
State the principle of working of a cyclotron. Write two uses of this machine.
A short bar magnet placed in a horizontal plane has its axis aligned along the magnetic north-sourth direction. Null points are found on the axis of the magnet at 14 cm from the centre of the magnet. The earth's magnetic field at the place is 0.36 G and the angle of dip is zero. What is the total magnetic field on the normal bisector of the magnet at the same distance as the null points (i.e. 14 cm) from the centre of the magnet? (at null points, field due to a magnet is equal and opposite to the horizontal component of earth's magnetic field).
A Kundt's tube apparatus has a steel rod of length 1.0m clamped at the centre. It is vibrated in its fundamental mode at a frequency of 2600Hz. The lycopodium powder dispersed in the tube collects into heaps separated by 6.5cm. Calculate the speed of sound in steel and in air.
What conclusion can you draw from the following observations on a resistor made of alloy manganin?
Current A
Voltage V
Current A
Voltage V
0.2 
0.4
0.6
0.8
1.0
2.0
3.94
7.87
11.8
15.7
19.7
39.4
3.0
4.0
5.0
6.0
7.0
8.0
59.2
78.8
98.6
118.5
138.2
158.0
What is the principle of superposition of charges?