Q1: 1. What is the unit of frequency modulation index in communication systems?

• A) Hertz
• B) Decibel
• C) Radian
• D) Percentage

Q2: 2. Which of the following is not a type of noise in communication systems?

• A) Thermal noise
• B) Shot noise
• C) Signal noise
• D) Flicker noise

Q3: 3. Which modulation technique is commonly used in television broadcasting?

• A) Amplitude modulation
• B) Frequency modulation
• C) Phase modulation
• D) Pulse modulation

Q4: 4. In communication systems, what is the purpose of a demodulator?

• A) To convert analog signals to digital signals
• B) To convert digital signals to analog signals
• C) To extract the original message signal from the modulated signal
• D) To amplify the signal for transmission

Q5: 5. Which of the following is an essential component of a communication system?

• A) Antenna
• B) Microphone
• C) Battery
• D) Speaker

Q6: 6. What is the bandwidth of a communication channel that can transmit frequencies from 10 kHz to 100 kHz?

• A) 90 kHz
• B) 100 kHz
• C) 110 kHz
• D) 1 MHz

Q7: 7. Which modulation technique is used in analog cell phone systems?

• A) Amplitude modulation
• B) Frequency modulation
• C) Phase modulation
• D) Quadrature modulation

Q8: 8. What is the main advantage of digital communication over analog communication?

• A) Higher bandwidth efficiency
• B) Easier implementation
• C) Less susceptible to noise
• D) Lower cost

Q9: 9. Which of the following is used for error detection in digital communication?

• A) Hamming code
• B) Gray code
• C) Excess-3 code
• D) BCD code

Q10: 10. What is the function of a repeater in communication systems?

• A) To amplify the signal
• B) To convert analog signals to digital signals
• C) To extract the message signal from noise
• D) To modulate the signal

Q11: 11. Which type of communication system is susceptible to fading due to multipath propagation?

• A) Analog
• B) Digital
• C) Satellite
• D) Microwave

Q12: 12. What is the modulation index of an amplitude modulated signal with a maximum amplitude of 8 V and a minimum amplitude of 2 V?

• A) 0.25
• B) 0.5
• C) 1
• D) 2

Q13: 13. Which of the following is not a type of digital modulation scheme?

• A) Amplitude Shift Keying (ASK)
• B) Frequency Shift Keying (FSK)
• C) Phase Shift Keying (PSK)
• D) Amplitude Modulation (AM)

Q14: 14. What is the primary purpose of a mixer in a communication system?

• A) To amplify the signal
• B) To combine multiple signals
• C) To convert the frequency of a signal
• D) To filter out noise

Q15: 15. Which type of modulation is commonly used in Wi-Fi communication systems?

• A) Amplitude modulation
• B) Frequency modulation
• C) Phase modulation
• D) Quadrature amplitude modulation

Q16: 16. What is the role of a low-pass filter in a communication system?

• A) To amplify high-frequency signals
• B) To block high-frequency signals
• C) To extract high-frequency components
• D) To combine multiple signals

Q17: 17. Which of the following is an example of a guided transmission medium in communication systems?

• A) Fiber optic cable
• B) Radio waves
• C) Infrared signals
• D) Satellite signals

Q18: 18. What is the main advantage of using frequency modulation (FM) for radio broadcasting?

• A) Better resistance to noise
• B) Higher power efficiency
• C) Easier demodulation
• D) Smaller bandwidth requirement

Q19: 19. Which type of antenna is commonly used in satellite communication systems?

• A) Yagi-Uda antenna
• B) Dipole antenna
• C) Helical antenna
• D) Parabolic antenna

Q20: 20. What is the function of a modem in a communication system?

• A) To encode digital data into analog signals
• B) To amplify the signal for transmission
• C) To decrypt encrypted messages
• D) To route data packets to the correct destination

Q21: 21. Which type of modulation is used in digital television broadcasting?

• A) Amplitude modulation
• B) Frequency modulation
• C) Quadrature amplitude modulation
• D) Vestigial sideband modulation

Q22: 22. What is the function of a multiplexer in communication systems?

• A) To amplify the signal
• B) To combine multiple signals into a single channel
• C) To extract the original message signal
• D) To modulate the signal

Q23: 23. Which of the following is not a type of digital communication system?

• A) Satellite communication
• B) Fiber optic communication
• C) Analog television broadcasting
• D) Cellular network

Q24: 24. What is the purpose of a transceiver in wireless communication systems?

• A) To amplify the received signal
• B) To encode digital data
• C) To transmit and receive signals
• D) To filter out noise

Q25: 25. Which type of modulation is commonly used in digital audio broadcasting (DAB) systems?

• A) Amplitude modulation
• B) Frequency modulation
• C) Phase modulation
• D) Orthogonal frequency-division multiplexing