Figure 1 shows a signal obtained after amplitude modulation by a sinusoidal message. The carrier frequency is difficult to determine from the figure, and is not needed for answering the questions below: a. Find the modulation index. b. Find the bandwidth of the AM signal.

The modulating signal directly deviates the carrier's frequency in this angle modulation. Select your answer. Direct FM Indirect FM Indirect PM Direct PM

Problem1: the figure shows multiple modulation schemes for the signal that is given by the dashed line sinusoidal function, the X-axis is the time axis is seconds and the Y-axis is the amplitude. Answer the following: 1. What is the modulation scheme in A? 2. What is the modulation scheme in B? 3. What is the sampling frequency? 4. What is the value of the duty cycle in A?

4. In an Amplitude Modulation: a) Amplitude of the carrier varies. b) Frequency of the carrier remains constant. c) Phase of the carrier remains constant. d) All of the above.

When an antenna is transmitting an unmodulated carrier, then the current is 10 amps and when the antenna is transmitting amplitude modulated signal, then the current is 15 amps. Estimate the modulation index. Round the answer to the nearest tenth.

When an antenna is transmitting an unmodulated carrier, then the current is 10 amps and when the antenna is transmitting amplitude modulated signal, then the current is 15 amps. Estimate the modulation index. Round the answer to the nearest tenth.

When an antenna is transmitting an unmodulated carrier, then the current is 10 amps and when the antenna is transmitting amplitude modulated signal, then the current is 15 amps. Estimate the modulation index. Round the answer to the nearest tenth.

1. What is the advantage of angle modulation for (noise and interference), the bandwidth of transmission and the average power of the transmission? comparison with the amplitude modulation

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A. (Look at the picture)  Which of the plots above shows the corresponding Fourier series amplitude spectrum? Hint: Count the number of cycles over samples (e.g. count how many big oscillations you see, corresponding to a low frequency component). Select one: a. Amplitude spectrum A b. Amplitude spectrum B c. Amplitude spectrum C d. Amplitude spectrum D =================== B. Look at 2nd picture: