ET263 Practice Test I

Instructions: There are 25 questions on this test. It is written in a style very similar to the REAL exam #1. Choose the best answer from among those given. Click the GRADE button on the bottom of the form when you want the exam graded.

Note: You can practice this test as many times as you desire; the system will cook you up a fresh batch of questions each time you access this page.

Your Name: @ 18.119.102.137

1. 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

2. 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

3. 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

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 is the wavelength of a 1 MHz signal?

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

6. Why is modulation and carrier transmission necessary in radio?

a) To keep antenna lengths reasonable
b) To allow stations to be separated by radio receivers
c) Both A and B
d) None of these

7. What type of filter is used to separate radio stations in a receiver?

a) Bandpass
b) Highpass
c) Lowpass
d) None of the above

8. 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

9. The signal shown above is fed into a bandpass filter with a center frequency of 2 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

10. The frequency-domain picture of an electronic signal is called a:

a) Spectrogram
b) Oscillogram
c) Noise Plot
d) None of the above

11. 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

12. 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

13. Which of these could be classified as an internal noise source?

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

14. What signal to noise ratio, in dB, will result if a system has 1 mV of noise and 1000 mV of signal voltage?

a) 10 dB
b) 20 dB
c) 60 dB
d) None of the above

15. Noise can best be defined as:

a) Any undesired signal within a system
b) Pulses appearing at the output of a system
c) Distortion at the output of a system
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 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

18. New frequencies that are generated during the process of modulation are known as:

a) Harmonics
b) Fundamentals
c) Sidebands
d) None of the above

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

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

20. 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

21. A certain AM transmitter produces 16W of power into a 50 Ohm load with no modulation. What total power will be produced at 50% modulation?

a) 17 W
b) 18 W
c) 20 W
d) None of the above

22. What is the total bandwidth of the AM signal pictured above?

a) 2 KHz
b) 700 KHz
c) 10 KHz
d) None of the above

23. What is the frequency of the upper sideband for an AM transmitter with a carrier frequency of 710 KHz and an information frequency of 5 KHz?

a) 710 KHz
b) 711 KHz
c) 712 KHz
d) None of the above

24. 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

25. 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


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