1) What is Electronic?-
Answer- The study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles are called electronics.
2) What is communication?
Answer- Communication is the way of transferring a signal from the transmitter which passes through a medium then the output is obtained at the receiver
3) Different types of communications? Explain.
Answer- Analog and digital communication.
Analog is the process of taking an audio or video signal (the human voice) and translating it into the electronic pulses. On the other hand, digital is breaking the signal into a binary format where the audio or video data is represented by a series of “1”s and “0”s.
Digital signals are immune to noise, the quality of transmission and reception is good, the components used in digital communication can be produced with high precision and the power consumption is also very less when it is compared with analog signals.
4) What is sampling?
Answer- The process of obtaining a set of samples from a continuous function of time x(t) is known as sampling.
5) State sampling theorem.
Answer- Sampling theorem states that, while taking the samples of a continuous signal, it has to be taken care that the sampling rate is equal to or greater than the twice of the cut-off – frequency and the minimum sampling rate is known as the Nyquist rate.
6) What is cut-off frequency?
Answer- The frequency at which the response is -3dB with respect to the maximum response is cut-off frequency.
7) What is the Pass Band?
Answer- The passband is the range of frequencies or wavelengths that can pass through a filter without being attenuated.
8) Describe Stop Band?
Answer- The stop band is a band of frequencies, between specified limits, in which a circuit, such as a filter or a telephone circuit, does not let signals through, or the attenuation is above the required stopband attenuation level.
9) Explain Rf?
Answer- Radio frequency (RF) is the frequency or rate of oscillation within the range of about 3 Hz to 300 GHz. This range corresponds to the frequency of the alternating current electrical signals used to produce and detect radio waves. Since most of the range is beyond the vibration rate that most mechanical systems can respond to, RF usually refers to oscillations in electrical circuits or electromagnetic radiation.
10) What is the modulation? And where it is utilized?
Answer- The process of varying some characteristic of a periodic wave with an external signal is modulation.
The radio communication superimposes this information bearing signal onto a carrier signal.
The high-frequency carrier signals can be transmitted over the air easily and are capable of traveling long distances.
The characteristics (amplitude, frequency, or phase) of the carrier signal are varied in accordance with the information bearing signal.
Modulation is utilized to send the information bearing signal over long distances.
11) What is demodulation?
Answer- Demodulation is the removal of the modulation from an analog signal to get the original baseband signal back. It is necessary because the receiver system receives a modulated signal with specific characteristics and it needs to turn it to base-band.
12) Name the modulation techniques.
Answer- For the Analog modulation–AM, SSB, FM, PM, and SM
For the Digital modulation–OOK, FSK, ASK, PSK, QAM, MSK, CPM, PPM, TCM, OFDM
13) Explain AM and FM.
Answer- AM stands for Amplitude modulation, is a type of modulation where the amplitude of the carrier signal is varied in accordance with the information bearing signal.
FM stands for Frequency modulation is a type of modulation where the frequency of the carrier signal is varied in accordance with the information bearing signal.
14) Where do we use AM and FM?
Answer- AM is used for video signals. For example TV. Ranges from 535 to 1705 kHz.
FM is used for audio signals. For example Radio. Ranges from 88 to 108 MHz.
15) What is the base station?
Answer- The base station is a radio receiver/transmitter that serves as the hub of the local wireless network, and may also be the gateway between a wired network and the wireless network.
16) How many satellites are required to cover the entire earth?
Answer- Three satellites are required to cover the entire earth, which is placed at 120 degrees to each other. The life span of the satellite is around 15 years.
17) What is a repeater?
Answer- The electronic device that receives a signal and retransmits it at a higher level or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances without degradation is called a repeater.
18) What is an Amplifier?
Answer- An electronic device or electrical circuit that is used to boost (amplify) the power, voltage or current of an applied signal.
19) What is Oscillator?
Answer- An oscillator is a circuit that creates a waveform output from the direct current input. The two main types of oscillator are:- harmonic and relaxation. The harmonic oscillators have smooth curved waveforms, while the relaxation oscillators have waveforms with sharp changes.
20) What is meant by impedance diagram?
Answer- The equivalent circuit of all the components of the power system are drawn and they are interconnected and is known impedance diagram.
21) What is an Instrumentation Amplifier (IA) and what are all the advantages?
Answer- A differential op-amp circuit providing high input impedances with ease of gain adjustment by varying a single resistor is known as an instrumentation amplifier.