RF and Wireless Communication – MCQs

1. : What does RF stand for in RF communication?
(A) Remote Frequency
(B) Radio Frequency
(C) Rapid Frequency
(D) Resonant Frequency

2. : Which frequency range is typically considered as RF?
(A) 3 Hz to 30 Hz
(B) 3 kHz to 300 GHz
(C) 300 GHz to 3 THz
(D) 30 MHz to 3 GHz

3. : Which modulation technique is commonly used in RF communication?
(A) Pulse Code Modulation
(B) Frequency Modulation
(C) Delta Modulation
(D) Differential PCM

4. : What is the main purpose of an antenna in a wireless system?
(A) Signal processing
(B) Frequency conversion
(C) Transmitting and receiving signals
(D) Signal amplification

5. : Wi-Fi typically operates at which frequency bands?
(A) 2.4 GHz and 5 GHz
(B) 900 MHz only
(C) 1 GHz and 2 GHz
(D) 3 MHz and 6 MHz

6. : Which of the following is a common RF connector type?
(A) USB
(B) HDMI
(C) SMA
(D) RJ45

7. : What is path loss in wireless communication?
(A) Increase in signal power over distance
(B) Reduction in signal strength due to obstacles and distance
(C) Amplification of signals in multipath
(D) Conversion of analog to digital signals

8. : Bluetooth operates in which frequency range?
(A) 900 MHz
(B) 1.2 GHz
(C) 2.4 GHz
(D) 5.8 GHz

9. : What is the unit of antenna gain?
(A) dBm
(B) dB
(C) dBi
(D) Hz

10. : Which type of antenna is commonly used in mobile phones?
(A) Dipole
(B) Yagi
(C) Patch
(D) Helical

11. : What does the acronym LTE stand for?
(A) Long Transmit Efficiency
(B) Low Transfer Energy
(C) Long-Term Evolution
(D) Low Time Error

12. : Which protocol is used in RFID systems?
(A) TCP/IP
(B) HTTP
(C) ISO/IEC 18000
(D) GSM

13. : In RF systems, what does VSWR stand for?
(A) Voltage Standing Wave Ratio
(B) Variable Sine Wave Resistance
(C) Voltage Signal Waveform Ratio
(D) Very Short Wave Reflection

14. : Which device is used to combine or split RF signals?
(A) Filter
(B) Oscillator
(C) Mixer
(D) Power Divider

15. : Which of the following is not a type of wireless modulation?
(A) AM
(B) FM
(C) PM
(D) PCM

16. : What is the wavelength of a 2.4 GHz signal in free space?
(A) 0.125 m
(B) 0.5 m
(C) 1.25 m
(D) 12.5 m

17. : Which type of polarization is typically used in satellite communication?
(A) Horizontal
(B) Vertical
(C) Circular
(D) Diagonal

18. : Which technology is based on spread spectrum technique?
(A) AM
(B) FM
(C) CDMA
(D) QPSK

19. : What is the purpose of an RF filter?
(A) To amplify signals
(B) To convert digital to analog
(C) To select or reject specific frequencies
(D) To generate carrier waves

20. : What is the full form of GSM?
(A) Global System for Mobile Communication
(B) General Satellite Modulation
(C) Global Satellite Messaging
(D) Group Signal Modulation

21. : The Doppler effect in RF communication affects:
(A) Amplitude
(B) Phase
(C) Frequency
(D) Wavelength only

22. : Which wireless technology is most suitable for short-range, low-power communication?
(A) WiMAX
(B) Zigbee
(C) LTE
(D) Satellite

23. : What causes fading in wireless communication?
(A) Noise in the signal
(B) Direct line-of-sight transmission
(C) Multipath propagation
(D) High antenna gain

24. : In RF systems, impedance matching is important for:
(A) Maximizing power transfer
(B) Increasing antenna length
(C) Reducing frequency
(D) Enhancing encryption

25. : Which of the following is a high-frequency band used in 5G communication?
(A) 700 MHz
(B) 2.4 GHz
(C) 3.5 GHz
(D) 26 GHz