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edc lab viva questions with answers pdf free

jaseela123d · 20-03-2017, 03:10 PM

Question No. 01: What is modulation?

Answer: Modulation is the process of varying some characteristics of a periodic wave with an external signal.

Radio communication superimposes this signal carrying information about a carrier signal.

These high frequency carrier signals can be easily transmitted through the air and are capable of traveling long distances.

The characteristics (amplitude, frequency or phase) of the carrier signal vary according to the carrier signal of information.

Modulation is used to send an information carrier signal over long distances.

Question No. 02: What is resistance?

Answer: A resistor is an electronic component of two terminals that opposes an electric current producing a voltage drop between its terminals in proportion to the current, ie, according to Ohm's law: V = IR.

Question No. 03: What is an amplifier?

Answer: The amplifier is an electronic device or electrical circuit that is used to increase (amplify) the power, voltage or current of an applied signal.

Question No. 04: What is the inductor?

Answer: An inductor is a passive electrical device used in electrical circuits for its inductance property. An inductor can take many forms.

Question No. 05: What is the op-amp?

Answer: An operational amplifier, often called an operational amplifier, is a high gain electronic voltage amplifier coupled to DC with differential inputs [1] and, usually, a single output. Typically, the output of the operational amplifier is controlled by negative feedback, which greatly determines the magnitude of its output voltage gain, or by positive feedback, which facilitates regenerative gain and oscillation.

Question No. 06: What is demodulation?

Answer: Demodulation is the act of removing the modulation of an analog signal to recover the original baseband signal. Demodulation is necessary because the receiving system receives a modulated signal with specific characteristics and needs to convert it into baseband.

Question No. 07: What is meant by impedance diagram?

Answer: We draw the equivalent circuit of all components of the power system and are interconnected is called the impedance diagram.

Question No. 08: What is the need for basic values?

Answer: The power system components can operate at different voltage and power levels. It will be desirable for analysis of the power system if the voltage, power, current ratings of the components of the power system are expressed with reference to a common value called the base value.

Question No. 09: Explain AM and FM?

Answer:

AM-Amplitude modulation is a type of modulation where the amplitude of the carrier signal varies according to the carrier signal of information.

FM-Frequency modulation is a type of modulation in which the frequency of the carrier signal varies according to the carrier signal of information.

Question No. 10: What is Electronics?

Answer: The study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles is called Electronic.

Question No. 11: What is the transistor?

Answer: In electronics, a transistor is a semiconductor device commonly used to amplify or change electronic signals. The transistor is the fundamental building block of computers, and all other modern electronic devices. Some transistors are packaged individually, but most are in integrated circuits.

Question No. 12: What are CDMA, TDMA and FDMA?

Answer: Code division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA employs extended spectrum technology and a special encoding scheme (where each transmitter is assigned a code) to allow multiple users to be multiplexed over the same physical channel. By contrast, time division multiple access (TDMA) divides access by time, while frequency division multiple access (FDMA) divides it by frequency.

An analogy to the problem of multiple access is a room (channel) in which people wish to communicate with each other. To avoid confusion, people can take turns talking (dividing time), speaking in different tones (frequency division), or speaking in different directions (spatial division). In CDMA, they would speak different languages. People who speak the same language can understand each other, but not other people.

Question No. 13: What is the need to study the flow of cargo?

Answer: The study of the load flow of an energy system is essential to decide the best existing operating system and to plan the future expansion of the system. It is also essential to design the energy system.

Question No. 14: Advantages of negative feedback on positive feedback?

Answer: Researchers have paid close attention to negative feedback processes, as negative feedback processes lead systems to equilibrium states. Positive feedback reinforces a given trend of a system and can drive a system away from equilibrium states, possibly causing rather unexpected results.

Question No. 15: What is communication?

Answer: Communication means transferring a signal from the transmitter that passes through a medium then the output is obtained at the receiver or communication said as message transfer from one place to another place called communication.

Question No. 16: What is the step band?

Answer: The passband is the range of frequencies or wavelengths that can pass through a filter without being attenuated.

Question # 17: Explain RF?

Answer: Radio Frequency (RF) is a frequency or rate of oscillation within the range of approximately 3 Hz to 300 GHz. This range corresponds to the frequency of electrical ac signals used to produce and detect radio waves. Since most of this range is beyond the speed of vibration at which most mechanical systems can respond, RF usually refers to oscillations in electrical circuits or electromagnetic radiation.

Question No. 18: What is the Instrumentation Amplifier (IA) and what are all the advantages?

Answer: An instrumentation amplifier is a differential op-amp circuit that provides high input impedances with easy gain adjustment by varying a single resistor.

Question No. 19: What is a semiconductor?

Answer: A semiconductor is a solid material that has an electrical conductivity between that of a conductor and that of an insulator (An insulator is a material that resists the flow of electric current, it is an object intended to support or separate electrical conductors without passing current Through himself); It can vary in that wide range permanently or dynamically.

Question No. 20: What is sampling?

Answer: The process of obtaining a set of samples from a continuous function of time x (t) is called sampling.

Question No. 21: Different types of communications?

Answer: The types of communications are analog and digital communications.

Analog Communication: As technology, analog is the process of taking an audio or video signal (the human voice) and translating it into electronic pulses. On the other hand, Digital is breaking the signal in a binary format where the audio or video data is represented by a series of "1" s and "0" s.

Digital communication: Digital signals are immune to noise, transmission quality and reception is good, the components used in digital communication can be produced with high precision and the power consumption is also much lower compared to analog signals .

Question No. 22: What is a base station?

Answer: The base station is a radio receiver / transmitter that serves as the hub of the local wireless network and can also be the gateway between a wired network and the wireless network.

Question No. 23: What are the main divisions of the electrical system?

Answer: The generator system, the transmission system and the distribution system.

Question No. 24: What is the Barkhausen criterion?

Answer: Criteria of Barkhausen, without which you will not know which conditions, must be satisfied by oscillations.

"The oscillations will not be sustained if, at the oscillator frequency, the magnitude of the output of the amplifier transfer gain and the magnitude of the feedback network feedback factor (the magnitude of the loop gain) are less than unity".

The unity loop gain condition - Aβ = 1 is called the Barkhausen criterion. This condition implies that

Aβ = 1 and that the -Aβ phase is zero.

Question No. 25: Example of Positive and Negative Feedback?

Answer: Example for + ve feedback is Oscillators and for -ve feedback is Amplifiers.

Question No. 26: State Sampling Theorem?

Answer: Indicates that when sampling a continuous signal, care should be taken that the sampling frequency is equal to or greater than twice the cutoff frequency and the minimum sampling rate is known as the Nyquist rate.

jaseela123d · 20-03-2017, 03:10 PM