On this page, we will review the Analog Electronics Short Notes PDF Part 21. Welcome to Poly Notes Hub, a leading destination for analog electronics notes for engineering students.
Author Name: Arun Paul
Analog Electronics Short Notes Pdf Part 21
Here we have listed some analog electronics short notes for all types of exams like diploma engineering, degree engineering, and GATE exam and many more. In every page, we have listed 10 short analog electronics questions and answers and anyone can download it by a single click for future use.
1. Which oscillator used in a Transmitter Circuit?
The Crystal Oscillator is commonly used in a transmitter circuit because it provides a highly stable and precise frequency signal required for modulation and transmission.
2. Which modulation is used in Radio Transmitter in India?
Amplitude Modulation (AM) is widely used for long and medium-wave radio transmission in India, especially in the MW and SW bands.
3. What is the Superheterodyne Principle?
The Superheterodyne Principle involves converting the incoming signal to a fixed intermediate frequency (IF) using a local oscillator and mixer, allowing easier and more effective amplification and filtering.
4. Why cannot electrical energy be radiated at lower frequency?
At lower frequencies, the wavelength becomes very large, requiring extremely long antennas and high power to radiate effectively. The radiation efficiency is very poor, making it impractical.
5. Why is radio transmission carried at high frequencies?
Radio transmission is carried at high frequencies because it improves radiation efficiency, allows smaller antennas, increases bandwidth, and supports long-distance communication through skywave or line-of-sight propagation.
6. What is importance of modulation factor in communication system?
The modulation factor indicates the depth of modulation in AM signals. It affects the signal strength, efficiency, and fidelity of transmission. Proper modulation ensures clear audio without distortion or over-modulation.
7. Why is AM and not FM employed for radio transmission in India?
AM is preferred for radio transmission in India because it requires simpler and cheaper receivers, covers larger distances, and works well with long and medium-wave bands, despite being more prone to noise than FM.
8. Why we selected IF as 455 KHz?
The IF value of 455 kHz is chosen in AM receivers because it offers a balance between good selectivity and gain, avoids interference from image frequencies, and fits well with available filter designs.
9. What is the importance of sideband frequencies?
Sideband frequencies carry the actual information (audio or data) in AM and other modulation types. Without sidebands, only the carrier would be transmitted, which contains no usable signal information.
10. Why is amplitude modulation gives noisy reception?
Amplitude modulation gives noisy reception because it is highly susceptible to amplitude variations caused by atmospheric noise, electrical appliances, and static interference, all of which affect the signal directly.