Electronic and Communications Interview Questions - Part 5
What is conductor ?
A substance, body, or device that readily conducts heat, electricity, sound, etc. Copper is a good conductor of electricity.
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.
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.
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.
What is op-amp ?
An operational amplifier, often called an op-amp , is a DC-coupledhigh-gain electronic voltage amplifier with differential inputs  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.
What is the difference between SCR and diode rectifier ?
Diode is a 2 terminal device, in scr gate controls the rectifing.SCR is used in High frequency applications but diode is low frequency devices, SCR can be in high temperatures but not diode.
What is intersymbol interference ?
In telecommunication, intersymbol interference (ISI) means a form of distortion of a signal that causes the previously transmitted symbols to have an effect on the currently received symbol. This is usually an unwanted phenomenon as the previous symbols have similar effect as noise, thus making the communication less reliable. ISI is usually caused by echoes ornon-linear frequency response of the channel. Ways to fight against intersymbol interference include adaptive equalization or error correcting codes (especially soft-decoding with Viterbi algorithm).
Distinguish between Angle modulation and Amplitude modulation.
In amplitude Modulation as the amplitude of given signal varies, the amplitude of carrier signal also varies in the same way. In angle modulation, the frequency or phase may vary according to the amplitude of given signal
What is Biasing ?
Biasing is a process of connecting dc voltage to a device by which we can select the operating point of the device. by biasing actually we select the operating point of the device.
What do you mean by ASCII, EBCDIC ?
ASCII (American Standard Code for Information Interchange), is a character encoding based on the English alphabet.
EBCDIC (Extended Binary Coded Decimal Interchange Code) is an 8-bit character encoding used on IBM mainframe operating systems