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1. Which of these describes the process of modulation?

a) Recovering information from a carrier wave
b) Placing information onto a carrier wave
c) Controlling the frequency of a carrier wave
d) None of the above

2. What is the wavelength of a 600 MHz signal?

a) 1 Meter
b) 0.5 Meter (50 cm)
c) 0.75 Meter
d) None of the above

3. What is the wavelength of a 1 MHz signal?

a) 100 Meters
b) 200 Meters
c) 300 Meters
d) None of the above

4. Which of these describes demodulation?

a) Recovering information from a carrier wave
b) Placing information onto a carrier wave
c) Controlling the frequency of a carrier wave
d) None of the above

5. What are the steps of troubleshooting in correct order?

a) Visual inspection, Check power supply, Check inputs & outputs
b) Check power supply, Visual inspection, Check inputs & outputs
c) Visual inspection, Check inputs & outputs, Check power supply
d) None of the above

6. In troubleshooting a stage in an electronic device, where is the best place to check the power supply?

a) At the output terminal of the voltage regulator IC
b) Directly at the terminals of the device using the power
c) At the power supply buss line
d) None of the above

7. A certain transmitter's antenna is 5/8 wavelength long and measures 49.213 inches. What is the actual operating frequency of this transmitter? (1 inch = 2.54 cm).

a) 25 MHz
b) 50 MHz
c) 75 MHz
d) 150 MHz
e) None of the above

8. Why can't audio frequencies be directly transmitted through an antenna system?

a) The antenna required would be too long
b) Too much power would be required
c) The receiver would distort the information waveform
d) None of the above

9. What is the only "pure" waveform containing no harmonic energies?

a) Triangle wave
b) Sine wave
c) Square wave
d) None of the above

10. What laboratory instrument is used to view signals in the frequency domain?

a) Oscilloscope
b) Function generator
c) Spectrum analyzer
d) None of the above

11. The signal shown above is fed into a bandpass filter with a center frequency of 1 KHz. What will the output of the bandpass filter look like on an oscilloscope?

a) A 1 KHz square wave
b) A 1 KHz sine wave
c) A 2 KHz triangle wave
d) None of the above

12. What is the frequency of the 3rd harmonic for the signal above?

a) 1 KHz
b) 2 KHz
c) 3 KHz
d) None of these

13. Which type of noise is caused by the thermal agitation of charge carriers within a conductor?

a) Atmospheric noise
b) Cosmic noise
c) Johnson noise
d) None of the above

14. What noise voltage will be generated across a 47K resistor at room temperature (24 degrees Celsius) if the circuit's bandwidth is 500 KHz? (k=1.38 x 10-23 J/K)

a) 40.5 uV
b) 19.6 uV
c) 20 uV
d) None of the above

15. To double the power of a Johnson noise source, what would be done?

a) Double the current
b) Double the bandwidth
c) Halve the resistance
d) None of the above

16. What noise voltage will be generated across a 100K resistor at room temperature (24 degrees Celsius) if the circuit's bandwidth is 1 MHz? (k=1.38 x 10-23 J/K)

a) 40.5 uV
b) 0.5 uV
c) 20 uV
d) None of the above

17. What is the information frequency in the AM signal pictured above?

a) 1 KHz
b) 2 KHz
c) 4 KHz
d) 5 KHz

18. If the load resistance RL is 50 Ohms, what is the total power of the AM signal above?

a) 200 Watts
b) 204 Watts
c) 250 Watts
d) None of the above

19. A certain AM transmitter produces 10W of power into a 50 Ohm load with no modulation. What total power will be produced at 100% modulation?

a) 15 W
b) 20 W
c) 30 W
d) None of the above

20. What bandwidth will be required to transmit a 2 KHz sine-wave tone on an AM carrier wave if the carrier frequency is 118 MHz?

a) 10 KHz
b) 4 KHz
c) 8 KHz
d) None of these

21. What bandwidth will be required to transmit a 5 KHz sine-wave tone on an AM carrier wave if the carrier frequency is 710 KHz?

a) 10 KHz
b) 5 KHz
c) 1 KHz
d) None of the above

22. What is the percentage of modulation of the AM signal pictured above?

a) 20%
b) 10%
c) 30%
d) None of the above

23. An AM transmitter is operating on a carrier frequency (Fc) of 10.000 MHz, with 5000 volts of carrier (Vc). The transmitter is operating at 70% modulation. What is the voltage in the upper side band?

a) 3500 V
b) 2750 V
c) 2000 V
d) 1750 V

24. An AM signal was measured on an oscilloscope. The readings were Vmax=400 V, and Vmin = 100V. What is the percent modulation?

a) 33.3%
b) 60 %
c) 75 %
d) None of the above

25. An AM transmitter is operating on a carrier frequency (Fc) of 1500 KHz, with 50 volts of carrier (Vc). The transmitter is operating at 90% modulation. What is the intelligence voltage (Vm or Vi)?

a) 50 V
b) 40 V
c) 45 V
d) None of these

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