Radio Frequency (RF) and Microwave – Multiple Choice Questions & Answers (MCQ3)

The Answers have been provided at the end of Questions.

Q1. What is the approximate bandwidth of radio frequency (RF) electromagnetic waves?

A. 300 Hz to 300 GHz

B. 20 Hz to 20 kHz

C. 300 Hz to 3000 GHz

D. 300 MHz to 300 GHz

Q2. In spectral analysis the following factors are considered except?

A. Power in band

B. Modulation factor

C. Harmonic distortion

D. Noise specification

Q3. What is power in band?

A. It is the measurement of frequency band or bandwidth that contains a specified percentage of the total power of the signal.

B. It is the measurement of total power within any specified frequency range or band.

C. It is a measure of how a particular channel and its adjacent channels distribute power.

D. None of the above.

Q4. What is the approximate bandwidth of microwave?

A. 10 kHz to 20 kHz

B. 3 Hz to 300 MHz

C. 0.3 GHz to 300 GHz

D. 20 Hz to 20 kHz

Q5. The following are true about harmonic distortion, except?

A. It is a measure of the amount of power contained in the harmonics of a fundamental signal.

B. It is determined by the smallest frequency that can be resolved.

C. Harmonics distortion can be expressed as either power or as percentage ratio.

D. Harmonic distortion is inherent to devices and systems that possess nonlinear characteristics.

Q6. Phase noises are due to?

A. Noise from other signals.

B. Modulation of the signal with the carrier signal.

C. Noise due to change of phase during transmission in different medium.

D. Noise due to change of phase during reflection.

Q7. The following sensors are used in measurement of power in RF & Microwave systems, except?

A. Thermistor

B. Strain gauge

C. Thermocouple

D. Barretter

Q8. Which of the following is a technique used in digital modulation?

A. Pulse shift keying

B. Frequency modulation

C. Frequency shift keying

D. None of the above

Q9. Which of the following is correct statement with regard to AM and FM signals?

A. FM signals are more immune to noise than AM signals.

B. FM signals can travel longer distance than AM signals.

C. Antennas for FM signals are larger in size than AM antennas.

D. Carrier frequencies of FM signals are relatively lower than AM signals.

Q10. Demodulation is done in the?

A. Transmitter

B. Receiver

C. Between the transmitter and radio receiver

D. None of the above

Q11. In AM wave, useful power is carried by?

A. Sidebands

B. Carrier

C. Both sidebands and carrier

D. None of the above

Q12. In an AM wave, the majority of the power is in the?

A. Upper band

B. Lower band

C. Carrier

D. None of the above

Q13. If the sweep generator output is directly connected to the input of the spectrum analyser, what will be displayed on the spectrum analyser?

A. Many random lines will be observed

B. A saw tooth wave can be observed

C. A single horizontal line can be observed

D. A single vertical line can be observed

Q14. The major advantage of FM over AM is?

A. Higher carrier frequency

B. Reception is less noisy

C. Smaller bandwidth

D. Small frequency deviation

Q15. The IF is 455 kHz. If the radio receiver is tuned to 855 kHz, what is the frequency of the local oscillator?

A. 1310 kHz

B. 1500 kHz

C. 2000 kHz

D. 455 kHz

Q16. Modulation refers to a low-frequency signal controlling the?

A. Frequency of the carrier

B. Amplitude of the carrier

C. Phase of the carrier

D. Can be any of the above

Q17. A high Q tuned circuit will allow an amplifier to have high

A. Sensitivity

B. Selectivity

C. Fidelity

D. Frequency

Q18. In Superheterodyne receiver, the input at the mixer stage is?

A. RF and AF

B. IF and RF

C. IF and AF

D. RF and local oscillator signal

Q19. What is the function of a scalar network analyser?

A. Measures the amplitude of an RF signal.

B. Measures the phase of an RF signal.

C. Is used to measure the frequency response of any device or system.

D. None of the above.

Q20. Most of the amplification in Superheterodyne receiver occurs at which stage?

A. RF amplifier

B. IF

C. Audio amplifier

D. Detector

Answers:

Q1. A, Q2. B, Q3. B, Q4. C, Q5. B, Q6. C, Q7. B, Q8. C, Q9. A, Q10. B, Q11. A, Q12. C, Q13. C, Q14. B, Q15. A, Q16. D, Q17. B, Q18. D, Q19. C, Q20. B

You can also read:

• Radio Frequency (RF) and Microwave Spectral Analysis
• Modulation in Communication Systems
• Demodulation in Telecommunication Systems
• Types of AM Radio Receivers
• Basics of Radio Frequency (RF) and Wireless Communication Systems