1. What is modulation in communication systems?
- A) Combining multiple signals into one
- B) Increasing the signal bandwidth
- C) Varying a carrier signal to encode information
- D) Converting analog signals to digital
Answer: C) Varying a carrier signal to encode information
2. Which of the following is an example of analog modulation?
- A) Amplitude Modulation (AM)
- B) Frequency Shift Keying (FSK)
- C) Phase Shift Keying (PSK)
- D) Quadrature Amplitude Modulation (QAM)
Answer: A) Amplitude Modulation (AM)
3. In Frequency Modulation (FM), which parameter of the carrier wave is varied?
- A) Amplitude
- B) Phase
- C) Frequency
- D) Power
Answer: C) Frequency
4. Which type of modulation is used in AM radio broadcasting?
- A) Frequency Modulation (FM)
- B) Amplitude Modulation (AM)
- C) Pulse Code Modulation (PCM)
- D) Phase Modulation (PM)
Answer: B) Amplitude Modulation (AM)
5. What does QAM stand for?
- A) Quadrature Amplitude Modulation
- B) Quantum Amplitude Modulation
- C) Quality Analog Modulation
- D) Quick Access Modulation
Answer: A) Quadrature Amplitude Modulation
6. Which of the following is NOT a digital modulation technique?
- A) Frequency Shift Keying (FSK)
- B) Phase Shift Keying (PSK)
- C) Amplitude Modulation (AM)
- D) Quadrature Amplitude Modulation (QAM)
Answer: C) Amplitude Modulation (AM)
7. What is the main advantage of digital modulation over analog modulation?
- A) Simpler implementation
- B) Less power required
- C) Better noise immunity
- D) Wider bandwidth
Answer: C) Better noise immunity
8. In Phase Shift Keying (PSK), which property of the carrier signal is varied?
- A) Amplitude
- B) Frequency
- C) Phase
- D) Power
Answer: C) Phase
9. Which modulation technique is most suitable for high-speed data transmission?
- A) AM
- B) FM
- C) PSK
- D) PCM
Answer: C) PSK
10. What does FSK stand for?
- A) Frequency Standard Keying
- B) Frequency Shift Keying
- C) Frequency Signal Keying
- D) Frequency Sampling Keying
Answer: B) Frequency Shift Keying
11. Which modulation technique combines amplitude and phase modulation?
- A) QAM
- B) PSK
- C) FSK
- D) FM
Answer: A) QAM
12. Which type of modulation is primarily used in mobile communication systems?
- A) FM
- B) QAM
- C) PCM
- D) CDMA
Answer: B) QAM
13. What does the term “carrier wave” mean in modulation?
- A) The wave that carries the information signal
- B) The wave used for demodulation
- C) The original information signal
- D) The wave that amplifies the signal
Answer: A) The wave that carries the information signal
14. Which modulation technique is used in television broadcasting?
- A) FM for audio and AM for video
- B) AM for both audio and video
- C) PCM for both audio and video
- D) FM for both audio and video
Answer: A) FM for audio and AM for video
15. Which of the following is a pulse modulation technique?
- A) Pulse Code Modulation (PCM)
- B) Frequency Modulation (FM)
- C) Amplitude Modulation (AM)
- D) Phase Modulation (PM)
Answer: A) Pulse Code Modulation (PCM)