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Basic Detail of Power Factor

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  Power Factor What is Power Factor ? It is the ratio of the active power of the fundamental wave the apparent power of  the fundamental waveform    Cause:    Inductive load which cause large difference of phase angle between current and voltage,Varying load,  industrial heating furnace, harmonic currents, electrical discharge lamp, AC motor, arc welder, furnaces, fluorescent lighting and air conditioning. Effect: overheating of motor and poor lightening.    Power factor correction: This is normally achieved by the addition of capacitors to the electrical network which compensate the active power. To reduce losses in the distribution system, and to reduce the clectricity bill, power factor correction, usually in the form of capacitors, is added to neutralize as ch of the magnetizing current as possible. Capacitor included leads the voltage, producing a leading power factor. The corrected power factor will be 0.92 to 0.95. Why to improv...
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Active and passive Instruments

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Active and Passive Instruments: Active and passive Instruments Passive Instruments: The instruments where the output is produced completely by the quantity that is measured are called passive instruments. The example of passive instrument is a pressure gauge.Fig  shows a pressure gauge. Passive  Instrument As the pressure in the liquid changes, the piston moves.The pointer is connected to the piston. No other source of energy is used. The liquid pressure is the only source. Thus,the piston and pointer movement while measurement is entirely dependent on the liquid pressure. Active Instruments: Active instruments are the instruments in which the quantity to be measured activates the magnitude of external power input source that produces the measurement. The liquid level indicator is an example of an active instrument.Fig.1.4.2 shows a liquid level indicator. Active Instruments The power source is required in or...
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Classification of Instrumentation System

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Classification of Instrumentation System Instrumentation system Null and Deflection type Instruments: Deflection type instruments: The instruments in which deflection of the instrument forms the basis of measuremenl are called as deflection type instruments. The example of deflection type instruments is the permanent magnet moving coil (PMMC) ammeter. PMMC AMMETER The deflection of the coil is proportional to the current that is to be measured. Torque Td, that acts on the moving coil is proportional to current.The opposing effect is produced by a spring, having torque Tc which is proportional to the deflection. When the spring is balanced Tc=Td. The value of the current depends on the deflection.Thus,the value of the measured quantity depends upon the calibration of the instrument. Null type Instruments The instrument in which, a null or zero indication will lead to the determination of the magnitude of the measured quantity such instruments are c...
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Ohm's Law | Basic Law of Electrical | Terms Related to Electrical

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Ohm's Law | Basic Law of Electrical | Terms Related to Electrical Ohm's Law  Ohm's law states that the current through any conductor is directly proportional to the potential difference between its ends, if the physical conditions of the conductor do not change. Ohm's Law | Basic Law of Electrical | Terms Related to Electrical That is, if temperature, length and cross sectional area of conductor are not changed then, I ∝ V  or  I = V / R or  V=IR where, V=voltage between ends of the conductor in volts I=current through the conductor in amperes. The V - I characteristics of it is shown in below figure. V - I  characteristics  If a curve is plotted between V and I it is found to be a straight line. All materials are broadly classified into three categories depending upon the resistance they offer to the flow of current through them. The electrical properties of the mate...
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BASIC OF CHARGE AND CURRENT

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 CHARGE AND CURRENT: CURRENT concept of charge is based on atomic theory. We know that all matter is made up of fundamental building blocks called atoms and that the atoms,in turn,are composed of different kinds of fundamental particles. The three most important particles are the electron,the proton,and the neutron. The electron possesses negative charge,the proton possesses equal-magnitude positive charge and the neutron have neutral or has no charge at all. As we rub the rubber comb with woolen cloth,the comb acquires its negative charge because some of the electrons on the wool are rubbed off on to the comb;the cloth then has an insufficient number of electrons to maintain its electrical neutrality and thus behaves as a positive charge. When electrons are removed from the substance,that substance becomes a positively charged and the substance acquiring electrons from the other substance becomes a negatively charged. The basic unit of the charge,called the ...
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