Electrical Heights

  Definition of Measurement and Calibration Measurement and Calibration Measurement: Measurement of a given quantity is the act or result of a quantitative comparison between an unknown quantity and a predefined standard quantity e.g.for measuring the weight of a quantity, the standard taken is 1 kg. Measurement  using an instrument as a physical means of determining a quantity or variable. Instrument: Define an instrument: Instrument can be defined as a device for measuring the value or magnitude of a quantity or variable. The electronic instrument is based on electrical or electronic principles for their measurement. Calibration: What do you mean by calibration?  Calibration is a process of estimating the value of a quantity by comparing that quantity with given standard quantity. The standard with which comparison is made is called as standard instrument. The unknown quantity is to be calibrated.This quantity is called as test quantity. If an

CLASSIFICATION OF NETWORKS Classification of Network The electrical networks may be classified in a number of ways depending upon following. (i)the kind of elements of which the network is composed of and on the basis of their properties (ii)in terms of the general properties of its responses to excitation applied to its input terminals.Thus,we have linear and non linear networks, time invariant and time variant networks, active and passive networks etc.   Linearity: In a linear network, the voltage-current relationship is show by a linear equation. Suppose the network to be classified is under relaxed condition such that the initial condition is zero and an excitation e1(t)is applied for which the response is c1(t)and for excitation e2(t), the response is c2(t).Then the network is classified as linear if for excitation e1(t)+e2(t), the response is c1(t)+c2(t).This shows that a linearity follows superposition principle. Hence,from physical point of view, it may be

 TYPES OF ELECTRIC ENERGY:     Electrical Energy in the methods of science,we immediately become suspicious of any scheme who claims to create energy. The law of conservation of energy is  that energy can neither be created nor destroyed. However, its form can be converted such that energy can be converted from one form of energy to another. Electric energy is the energy who converted from some other form. There are a numbers of way in which this is accomplished. Some of them are as follows: (1)Electrochemical energy conversion: Electric batteries produce electric energy with  the help of  conversion of chemical energy. A potentially important use of this type of batteries is in the electric car. Fuel cell is in this general classification. (2)Electromechanical energy conversion: The rotating generator produces electric energy from mechanical energy of rotation. Usually, the mechanical energy who converted from thermal energy by a turbine and, in turn

 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 Coul

Difference Between Slip ring and Squirrel cage induction motor Difference Between Squirrel cage and Slip ring inductio motor Slip ring or phase wound Induction motor 1.Construction is complicated due to presence of slip ring and brushes. 2.The rotor winding is similar to the stator winding. 3.We can easily add rotor resistance by using slip ring and brushes. 4.Due to presence of external resistance high starting torque can be obtained. 5.Slip ring and brushes are present. 6.Frequent maintenance is required due to presence of brushes. 7.The construction is complicated and the presence of brushes and slip ring makes the motor more costly. 8.This motor is rarely used,only 10% industry uses slip ring induction motor. 9.Rotor copper loss is high and so less efficiency. 10.Speed control by rotor resistance method is possible. 11.Slip ring induction motor.is used where high starting torque is required i.e.   in hoists, cranes, eleva

Voltage Regulator  and Review of Basic DC-DC Voltage Regulators The regulated output DC voltage can be obtained using either linear power supply or switched mode power supply. Linear power supply consist of devices that operate in active regions to regulate the DC output voltage. the block diagram of linear power supply is shown in below figure: The transistor T1 is connected in series with the DC source voltage. Here note that the series transistor T1 operates in active region. The error amplifier compare the output voltage Vo(av) with set value Vref. The difference between Vo(av) and Vref is called error voltage. it is given to control circuit. The control circuit generates the base drive of T1 in such a ways that error voltage is zero this means Vo(av)=Vref The output voltage Vo(av)=Vs-Vce. This means the transistor T1 has the power loss of Vce x io. This loss takes place continuously across T1. Because of this reason, linear power supply has reduce

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 materials largely