ENGINEERING ARTICLES

Graduate Assessment Test GAT™-GENERAL is for admissions in MS / M.Phil programs. The test result will remain valid for "TWO YEARS" for admissions. Candidates with a minimum of sixteen years of education are eligible to appear in the test. Candidate intending to improve their previous GAT™ score can also apply.  The candidates will have to qualify other specified criteria of the Universities. Mobile phones are not allowed in test center premises. The GAT™ test validity (GAT™ - General / Subject) for TWO YEARS will be effective from 1st January 2007 onwards. Category Test Type Verbal Reasoning Quantitative Reasoning Analytical Reasoning Tota l GAT™-A Paper Distribution GAT™ A Business and Engineering Students 35% 35% 30% 100% GAT™-B Paper Distribution GAT™-B Art, Humanities and Social Sciences Students 50% 30% 20% 100% GAT™-C Paper Distribution GAT™-...

Electrical Engineering Objective Type By M. Handa & A. Handa Index Electrical Current & Ohms Law Source of EMF AC Fundamentals RLC Circuits Network Theory Control System Engineering Materials Electrostatics Magneto Statics Electromagnetics Vacuum Tubes Semi-Conductors Transistors Amplifiers Oscillators Digital Electronics DC Generators DC Motors Transformers Synchronous Generators Synchronous Motors Induction Motors Single Phase Motors Generation of Electrical Power Economics of Power Generation Transmission & Distribution Circuit Breakers Transmission Lines & Cables High Voltage Engineering Rectifiers & Converters Illumination Electric Traction Heating & Welding Electrical Machine Design Industrial Drives Instruments & Measurement Power Electronics Computation Model Papers Click here to download Note:  Use any proxy server if found 8 hours delay or any other error and change your location to US...

INTELLIGENT : capable of sensing system overloads and rerouting power to prevent or minimize a potential outage; of working autonomously when conditions require resolution faster than humans can respond…and cooperatively in aligning the goals of utilities, consumers and regulators EFFICIENT: capable of meeting increased consumer demand without adding infrastructure ACCOMMODATING: accepting energy from virtually any fuel source including solar and wind as easily and transparently as coal and natural gas; capable of integrating any and all better ideas and technologies energy storage technologies, for example – as they are market-proven and ready to come online MOTIVATING: enabling real-time communication between the consumer and utility so consumers can tailor their energy consumption based on individual preferences, like price and/or environmental concerns OPPORTUNISTIC: creating new opportunities and markets by means of its ability to capitalize on plug-a...

A protective relay is a device that detects the fault and initiates the operation of the circuit breaker to isolate the defective element from the rest of the system. The relays detect the abnormal conditions in the electrical circuits by constantly measuring the electrical quantities which are different under normal and fault conditions. The electrical quantities which may change under fault conditions are voltage, current, frequency and phase angle. Through the changes in one or more of these quantities, the faults signal their presence, type and location to the protective relays. Having detected the fault, the relay operates to close the trip circuit of the breaker. This results in the opening of the breaker and disconnection of the faulty circuit. A typical relay circuit is shown in Figure. This diagram shows one phase of 3-phase system for simplicity. The relay circuit connections can be divided into three parts viz. First part is the primary winding of a cur...

The use of semi-conductors in place of mechanical switches is what makes a circuit “electronic,” because they enable electrical signals to be switched at extremely high speeds, which is not possible with mechanical circuits. There are many different semi-conductor. DIODE: Like a one-way valve for electrical current, this device enables only electrical current to pass through it in one direction–extremely useful by itself, but also the basis for all solid state electronics. LIGHT EMITTING DIODE (LED): This type of diode emits a small amount of light when electrical current passes through it. LIGHT DEPENDENT RESISTOR (LDR): This type of semi-conductor has a changing resistance, depending on the amount of light present. BIPOLAR JUNCTION TRANSISTOR (BJT): This is a current-driven electronic switch used for its fast switching properties. METAL-OXIDE SEMICONDUCTOR FIELD-EFFECT TRANSISTOR (MOSET): This is a voltage-driven electronic s...

Although both transistors and grid-controlled tubes (e.g. triode, tetrode and pentode) can render the job of amplification, they differ in the following respects: The electron tube is a voltage driven device while transistor is a current operated device. The input and output impedances of the electron tubes are generally quite large. On the other hand, input and output impedances of transistors are relatively small. Voltages for transistor amplifiers are much smaller than those of tube amplifiers. Resistances of the components of a transistor amplifier are generally smaller than the resistances of the corresponding components of the tube amplifier. The capacitances of the components of a transistor amplifier are usually larger than the corresponding components of the tube amplifier.

It is assumed here that the transmission has multiple grounding points at wye connected transformer neutrals, located throughout the system. When this condition is satisfied, any arcing fault between a phase conductor and the ground will be supplied by zero-sequence currents originating in the neutral connection of the high-voltage transformer banks. We often refer to these neutral connections as the "sources" of ground current, since very little current would flow to the ground fault if there were no grounded neutrals to provide a complete circuit for the fault current. When there are multiple ground sources, the current flowing to the ground may be very large. Any current flowing to the ground contains zero-sequence components and, under grounded conditions, a zero-sequence voltage will be measured at any nearby relay installation. Negative-sequence currents and voltages will also be observed, and these are sometimes used by the protective system. However, most ground ...