Electrical engineering

Definition: A transformer is a static electromagnetic energy conversion device, that transfers electrical energy from one circuit to another circuit without change in frequency. An induction motor is a electromechanical energy conversion device, that converts electrical energy into mechanical energy. Difference Between a Transformer and an Induction Motor In general, an induction motor is a rotating transformer with primary winding connected to supply mains and the secondary winding terminals are shorted. However, the difference between a transformer and an induction motor are mentioned below: Transformer is a static machine whereas an induction motor is a rotating machine. Transformer is an electromagnetic energy conversion machine wheras an induction motor is an electromechanical energy conversion machine. Transformer is a constant frequency device wheras in an induction motor the stator is at supply frequency(f) but rotor is at frequency "s*f", where "s" is cal...

Definition: The transformer is an electromagnetic energy conversion device, that transfers electrical energy from one circuit to another circuit without any change in frequency.  During this process of energy transfer, the energy is being converted from electrical to magnetic and back again to electrical energy. The part of the transformer that receives electrical energy from supply mains is known as a primary winding and the part that delivers electrical energy to the load is known as the secondary winding. Single phase transformer The primary and secondary windings of the transformer are not electrically connected but are magnetically coupled. Thus, the electrical energy received by the primary winding is first converted into magnetic energy and then it is converted back into electrical energy in the secondary winding. Working Principle of transformer: The basic working principle of a transformer is "faraday's law of electromagnetic induction" .      According to f...

This posts will provide you MCQ's on power system chapter-1 Generation. This MCQ's will help you to clear various state electricity board exams and also helps in interviews. Power system is a subject that deals with the generation, transmission, distribution and the utilization of electrical energy. For an electrical engineer, it is a very important and core subject. MCQs on Power Systems Chapter-1 Generation 1) Which is not a non conventional energy sources? Solar Diesel Biomass Hydro 2) Which type of generator are used for non renewable power generation? DC generator Induction generator Synchronous generator All of the above 3) A generating station which converts heat energy from the combustion of coal into electrical energy is known as _________? Steam power station. Nuclear power station Geothermal power station Biomass power station 4) Which power stations comes under the category of peak load plants? Nuclear power plant Hydro power plant Wind power plant Solar power plant...

Definition: A power system can be defined as a system that deals with the principles of generation, transmission, distribution, and utilization of electrical energy. The single line diagram of a power system network is as shown below Generally, most of the time the power system network operates in normal conditions i.e the electrical quantities like voltage, current, and frequency are within the specified limits. But sometimes the network may experience some abnormal conditions in the electrical quantities due to the occurrence of faults. Now, we cannot stop the occurrence of these faults since the overhead lines are exposed to atmospheric conditions.  Classifications of faults The electrical faults are generally classified as: Open circuit faults Short circuit faults However, they are further classified as: Open circuit faults occur in series with lines so they are generally called series faults. these faults occur due to the melting of conductors, snatching of conductors du...

A generator is an electrical machine that converts mechanical energy into electrical energy.  Generators are generally classified as below: Synchronous generator Vs. Induction generator The difference between  Synchronous generator and Induction generator is as mentioned below: 1) Synchronous generator The field is excited by an external D.C excitation and the rotor is connected to prime mover. The synchronous generator always operates at synchronous speed (Ns). Since, the field is excited by an external D.C source, the synchronous generator can deliver both the real/true and reactive power. Real power is being supplied by prime mover input and reactive power is supplied by external D.C excitation connected to the field.  Hence, both real and reactive supplied can be controlled. Since, the reactive power can be fully controlled, the synchronous generator can be operated at all range of power factors (Lagging, Leading, Unity power factor). Efficiency is good. Suitable for ...

Many of us know that, in electrical power generation the frequency must be kept constant for satisfactory operation of power system. But, the question is, why the frequency is to made constant?  Before this, let us first understand the basic operation of the alternator. Operation of alternator: An alternator (synchronous generator) is a machine which converts mechanical energy into electrical energy at a particular voltage but at a constant frequency. The rotor part consist of field winding and stator part consist of armature winding. The field winding is excited with D.C supply. The turbine is mechanically coupled with the rotor to give the mechanical power input to the alternator. Now, when rotor rotates the flux due to field winding cuts armature conductors and according to the faraday's law of electromagnetic induction, an emf is induced in the armature conductors. The frequency of induced emf is given by: So, to generate constant frequency, the machine must always be driven at...

Which are the must conditions to be fulfilled for the operation of an Electric Motor? An electric motor is an electro-mechanical energy conversion device i.e converts electrical energy into mechanical energy. The motors are generally classified as: D.C motors. A.C motors. Operating principle It works on the principle of lorent'z force law i.e " Whenever a current carrying conductor placed inside a magnetic field experiences a force". Conditions for the operation of an electric motor For any type of motor, the two conditions are must to be satisfied. They are as follows: There must be the interaction of two magnetic fields. Both the magnetic field must be stationary with respect to each other i.e relative speed between two fields must be zero. The number of stator poles and rotor poles must be same. What happens if this conditions are not satisfied? The operation of an electric motor depends on the presence of electromagnetic torque. The expression for electromagnetic torq...

How to measure an inductance of a coil without using LCR meter? To measure the inductance of a coil , one can use a LCR meter. But, measuring the inductance of the coil without LCR meter is also not a difficult task. We can do it in a simple way by using some mathematical expressions. Consider a coil as shown above whose inductance is to be measured and then follow these steps:- 1) Take a battery and an ammeter and connect them in series with coil. Take a voltmeter and measure the battery voltage. The ammeter will give current through the coil. The voltmeter will give voltage across the coil. Then find resistance of the coil by using mathematical expression 2) Disconnect the battery and connect an A.C source of some frequency "f" hz across the coil. Then using voltmeter and ammeter reading, find the impedence of the coil by using mathematical expression Now, as we have the impedence of the coil and resistance of the coil, we can now find the inductive reactance of the coil us...