Average Value of Alternating QuantityThe arithmetical average of all the instantaneous values of an alternating quantity over one cycle is known as the "Average Value of Alternating Quantity".$$Average\:value=\frac{Sum\:of\:all\:instantaneous\:values\:over\:one\:cycle}{Number\:of\:instants}$$$$=\frac{Total\:are\:under\:the\:curve\:for\:time\:period\:T}{Time\:Period\:(T)} $$$$=\frac{i_{1}+i_{2}+i_{3}+...+i_{n}}{n}$$Average Value of Symmetrical WavesIn case of symmetrical waves like sinusoidal voltage or current, the average value over one cycle is zero. It is because the positive half cycle is exactly equal to the negative half cycle. But the average value of positive or negative half cycle is not zero. Therefore, in case of symmetrical waves, the average value is calculated for half cycle.$$Avg\:value = \frac{Sum\:of\:all\:instantaneous\:values\:over\:half\:cycle}{Number\:of\:instants\:of\:half\:cycle}$$Average Value of Unsymmetrical WaveIn case of ... Read More

A unit of measurement can be defined as a quantity chosen as a standard in terms of which other quantities may be expressed.Engineering is an applied science dealing with a variety of physical quantities (a physical quantity is one which can be measured) like time, speed, voltage, resistance etc. Hence, for the measurement of these quantities standard units are defined.There are a number of electrical units defined which are based on the SI system of units.Standard Electrical Units of MeasurementElectrical QuantitySymbol for QuantityMeasuring UnitSymbol for UnitChargeQ or qCoulombCVoltageV or vVoltVEMFE or eVoltVCurrentI or iAmpereAResistanceR or rOhmΩInductanceLHenryHCapacitanceCFaradFConductanceGMho or Siemen℧ or Ω-1or ... Read More

A band pass filter (BPF) is a circuit that passes frequencies within a certain range and rejects all the frequencies outside the range. This range of band pass filter is known as Bandwidth of the filter.The Bandwidth of band pass filter is given by, $$Bandwidth=f_{high}-f_{low}$$Where, fhigh and flow are the higher and lower cut off frequencies.The values of fhigh and flow are given by, $$f_{high}=\frac{1}{2\pi\:R_{2}C_{2}}$$$$f_{low}=\frac{1}{2\pi\:R_{1}C_{1}}$$In the frequency response curve or bode plot of the band pass filter, the signal is blocked(attenuated) at low frequencies with the output increasing at the rate of +20dB/Decadeuntil the frequency reaches the Lower Cut off ... Read More

Wires and TracesComponent NameSymbolWires or ConductorTrace Junction or Connected WiresTrace Crossing or Unconnected WiresGroundsComponent NameSymbolGround or EarthSignal GroundChassis GroundSourcesComponent NameSymbolSingle CellBattery (Combination of cells)Photovoltaic Cell (Solar Cell)Independent or Constant Voltage SourceControlled or Dependent Voltage SourceIndependent or Constant Current SourceControlled or Dependent Current SourceAC voltage SourceResistorsComponent NameSymbolFixed ResistorRheostat (Variable Resistor)PotentiometerThermistor or VaristorCapacitorsComponent NameSymbolNon-polarized CapacitorPolarized CapacitorVariable CapacitorTrimmer CapacitorInductorsComponent NameSymbolAir Cored InductorIron Cored InductorTapped InductorTransformersComponent NameSymbolTransformerCenter Tapped TransformerStep up TransformerStep Down TransformerTransformer with two secondary windingsCurrent TransformerPotential TransformerZero Sequence Current Transformer (ZSCT)DiodesComponent NameSymbolPN Junction DiodeSchottky DiodeZener DiodeLight Emitting Diode (LED)Photo DiodeTunnel DiodeVaricap (Variable Capacitor Diode)Schockley DiodeConstant Current DiodeSilicon Controlled Rectifier (SCR)DiacTransistorsComponent NameSymbolN-channel, Junction ... Read More

An electrodynamometer or simply Dynamometer wattmeter is an instrument that is universally used for the measurement of DC as well as AC electric power.It works on the principle of dynamometer i.e. a mechanical force acts between two current carrying conductors.Construction of ElectrodynamometerThe electrodynamometer wattmeter has a fixed coil divided into two parts and is connected in series with the load and caries the load current (I1). The moving coil is connected across the load through a series multiplier resistance (R) and carries a current (I2) proportional to the load voltage. The fixed coil is called as Current Coil and the ... Read More

A magnet whose magnetic field is created by an electric current is known as Electromagnet. An electromagnet consists of a soft iron core wound with a coil of conductor wires.When a direct electric current is passed through the coil of the electromagnet a magnetic field is created around it. Since the magnetic field of electromagnet is a function of electric current flowing through the coil hence, the magnetic field can be alter by changing the amount of electric current. And its polarity can be changed by changing the direction of electric current.Electromagnets are temporary magnets because they can be demagnetized ... Read More

To understand the transient response of the first order system, consider the block diagram of a closed loop system with unity negative feedback.The open loop gain G(s) of the system with unity negative feedback is given by, $$G(s)=\frac{1}{s\tau}$$And the closed loop transfer function of the system with unity negative feedback is, $$\frac{C(s)}{R(s)}=\frac{G(s)}{1+G(s)}=\frac{1}{s\tau+1}\:\:\:...(1)$$Where, R(s) = Laplace transform of the input signal r(t), C(s) = Laplace transform of the output signal c(t), τ = Time Constant of the system.As we can see, the power of s is one in the denominator term of the closed loop transfer equation. Hence, the system is said to ... Read More

Jean Baptiste Joseph Fourier developed a technique to analysing non-sinusoidal waveforms applicable to a wide range of engineering problems. Many times all the information available in time domain is not sufficient for the analysis of the circuits, for this reason we have to transform the signal into frequency domain for extracting more information about the signal. The Fourier series is a tool used for transforming a signal from time domain to the frequency domain. In the Fourier series the signal is decomposed into harmonically related sinusoidal functions.Frequency Domain AnalysisA periodic signal can be decomposed into a linear weighted sum of ... Read More

The static electricity is the result of an imbalance between the positive and negative charges of an object.To understand the phenomena of static electricity, first we need to understand the basics of atoms and charges.The Structure of AtomAll the physical objects are made up of atoms. The atoms in turn made up of electrons, protons and neutrons. The electrons are negatively charges, protons are positively charged and the neutrons does not possess any charge. Therefore, all the physical objects are made up of charges.The opposite charges (positive and negative) attract each other while the like charges (positive and positive or ... Read More

The Bode Plot is the frequency response plot of linear systems represented in the form of logarithmic plots. In bode plot the horizontal axis represents frequency on a logarithmic scale and the vertical axis represents either the amplitude or the phase of the frequency response function.Low Pass Filter Bode PlotThe frequency response function or transfer function of the RC low pass filter is given by, $$\frac{V_{out}}{V_{in}}=\frac{A}{1+(j\omega\:T)}=\frac{A}{1+(j\omega\:/\omega_{0})}=\frac{A}{\sqrt{1+(\omega\:/\omega_{0})^{2}}}\angle\:-\tan^{-1}(\frac{\omega}{\omega_{0}})$$Where, T = Time constant of the circuit = $1/\omega_{0}=RC$A = Constant and$\omega_{0}$ = Cut off frequencyBode Magnitude Plot of LPFThe magnitude plot can be obtained from the absolute value of transfer function i.e.$$|\frac{V_{out}}{V_{in}}|=20\log_{10}\frac{|A|}{|1+j\omega\:/\omega_{0}|}$$When $\omega\:\omega_{0}$ ... Read More