Q & A: Electronics and Communication Engineering

1) Expand ECE.

Electronics & Communication Engineering.

 2) What is Electronic?

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

 3) What is communication?

Communication means transferring a signal from the transmitter which passes through a medium then the output is obtained at the receiver. (or)communication says as transferring of message from one place to another place called communication.

4) Different types of communications? Explain.

Analog and digital communication.

As a technology, analog is the process of taking an audio or video signal (the human voice) and translating it into electronic pulses. Digital on the other hand 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, quality of transmission and reception is good, components used in digital communication can be produced with high precision and power consumption is also very less when compared with analog signals.

5) What is engineering?

The application of science to the needs of humanity and a profession in which a knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with judgment to develop ways to use economically the materials and forces of nature for the benefit of mankind.

6) Difference between electronic and electrical.

Electronics work on DC and with a voltage range of -48vDC to +48vDC. If the electronic device is plugged into a standard wall outlet, there will be a transformer inside which will convert the AC voltage you are supplying to the required DC voltage needed by the device. Examples: Computer, radio, T.V, etc...

Electric devices use line voltage (120vAC, 240vAC, etc...). Electric devices can also be designed to operate on DC sources, but will be at DC voltages above 48v. Examples: are incandescent lights, heaters, fridge, stove, etc...

 7) What is sampling?

The process of obtaining a set of samples from a continuous function of time x(t) is referred to as sampling.

8) What is a rectifier?

A rectifier changes alternating current into direct current. This process is called rectification. The three main types of rectifier are the half-wave, full-wave, and bridge. A rectifier is the opposite of an inverter, which changes direct current into alternating current.

HWR- The simplest type is the half-wave rectifier, which can be made with just one diode. When the voltage of the alternating current is positive, the diode becomes forward-biased and current flows through it. When the voltage is negative, the diode is reverse-biased and the current stops. The result is a clipped copy of the alternating current waveform with only positive voltage, and an average voltage that is one third of the peak input voltage. This pulsating direct current is adequate for some components, but others require a more steady current. This requires a full-wave rectifier that can convert both parts of the cycle to positive voltage.

FWR- The full-wave rectifier is essentially two half-wave rectifiers, and can be made with two diodes and an earthed centre tap on the transformer. The positive voltage half of the cycle flows through one diode, and the negative half flows through the other. The centre tap allows the circuit to be completed because current cannot flow through the other diode. The result is still a pulsating direct current but with just over half the input peak voltage, and double the frequency.

9) What is resistor?

A resistor is a two-terminal electronic component that opposes anelectric current by producing a voltage drop between its terminals in proportion to the current, that is, in accordance with Ohm's law: V= IR.

10) What is capacitor?

A capacitor is an electrical/electronic device that can store energyin the electric field between a pair of conductors (called "plates"). The process of storing energy in the capacitor is known as "charging", and involves electric charges of equal magnitude, but opposite polarity, building up on each plate.

Capacitors are occasionally referred to as condensers. This term is considered archaic in English, but most other languages use acognate of condenser to refer to a capacitor.

11) What is inductor?

An inductor is a passive electrical device employed in electrical circuits for its property of inductance. An inductor can take many forms.

41) What is conductor?

A substance, body, or device that readily conducts heat, electricity, sound, etc. Copper is a good conductor of electricity.

12) What is a semi conductor?

A semiconductor is a solid material that has electrical conductivityin between that of a conductor and that of an insulator(AnInsulator is a material that resists the flow of electric current. It is an object intended to support or separate electrical conductorswithout passing current through itself); it can vary over that wide range either permanently or dynamically.

13) What is diode?

In electronics, a diode is a two-terminal device. Diodes have two active electrodes between which the signal of interest may flow, and most are used for their unidirectional current property.

14) What is transistor?

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

15) What is op-amp?

An operational amplifier, often called an op-amp , is a DC-coupledhigh-gain electronic voltage amplifier with differential inputs[1] and, usually, a single output. Typically the output of the op-amp is controlled either by negative feedback, which largely determines the magnitude of its output voltage gain, or by positive feedback, which facilitates regenerative gain and oscillation.

16) State sampling theorem.

It 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 twice the cut off frequency and the minimum sampling rate is known as the Nyquist rate.

17) What is cut-off frequency?

The frequency at which the response is -3dB with respect to the maximum response.

18) What is pass band?

Passband is the range of frequencies or wavelengths that can pass through a filter without being attenuated.