In an Amplitude Modulator where the carrier and modulating signals are both sine waves, the frequency spectrum of the resulting AM signal is shown below. 12V 2V 2V kHz 803 808.6 a) Determine the equation of the modulating signal b) Calculate the bandwidth of the AM signal c) Calculate the effective current of the AM signal thru a 75-ohm load. d) Sketch the AM wave and label the maximum and minimum voltage of the signal.

2. Plot the transfer function, and clearly indicate the on/off conditions of each diode, the slope of the line, and the voltages of turning points in each operating region for the following circuits. Assuming the constant-voltage model (VD,on = 0.8 V) is used to determine the DC level. Also, Plot the output waveform in time-domain if the input signal is as shown below with the amplitude and other important values labeled in the figure. (a) (b) Vin R= 500 D₁ V₁= 2.5 V D₂ A V₂ 1.6 V D₁ 2R 2X4 2R D₂ 3R out Vout Vin Vin 10 mv 1-AAAA-3.4 V >t 5 V

5) An LED light is powered by a 20V DC (low:0V to high:20V) square wave source in frequency of 1.2KHZ. Find the power delivered (average) to the LED light when the square wave is in 30%, 50%, and 80% duty-cycle respectively.

1) In the context of semiconductors, describe the following:(a) Intrinsic and extrinsic semiconductor. (b) Drift velocity of carriers.(c) Band-gap energy.(d) Frequency of light emitted by an LED.