DC Generator Generator principle An Electric generator is a machine that converts mechanical energy into electrical energy. It is based on the principle that whenever flux is cut by a conductor, an emf is induced which will cause a current to flow if ,the conductor circuit is closed. The direction of induced emf is given … Read more
Resonance in parallel A.C circuits (Parallel Resonance) An electrical circuit containing reactive elements(L and C) is said to be in resonance if the circuit power factor is unity. If it happens in a series a.c circuit (i.e R-L-C series circuit),it is called series resonance. If this condition(i.e unity p.f) occurs in a parallel a.c circuit .it … Read more
Resonance in AC Circuit An ac circuit containing reactive elements(L and C) is said to be in resonance when circuit power factor is unity. Resonance means to be in step with. When applied voltage and circuit current in an ac circuit are in step with(i.e phase angle is Zero or power factor is unity) the … Read more
RLC Series Circuit The RLC Series Circuit is a circuit which consist of a pure resistance of R ohms, a pure inductance of L Henry and a pure capacitance of C farads connected together in series combination with each other. voltage across R ,VR=IR where VR is in phase with I. voltage across C, … Read more
RC Series Circuit A circuit that contains pure resistance R ohms connected in series with a pure capacitor of capacitance C farads is known as RC Series Circuit. Let , V=rms value of applied voltage I=rms value of the circuit current Voltage across R ,VR=IR where VR is in phase with I. voltage across … Read more
RL series circuit A.C circuit Ac series circuit differ from dc circuit. In dc circuit we consider resistance only but in case of Ac series circuit resistance(R) ,inductance(L) and Capacitance(C) are taken into account. L & C offer opposition(XL and XC) to the flow of current in ac circuit. The magnitude of current in an … Read more
Measurement of Reactive Volt- AMPERES For the measurement of reactive power in a single-phase circuit we used compensated wattmeter. In compensated wattmeter the voltage applied to the pressure coil is 90° out of phase with the actual voltage and the wattmeter will read the reactive power VI cos(90° – Φ) i.e VI sinΦ.In single-phase measurement the … Read more
Two Wattmeter Method Two wattmeter method is generally used for measurement of power in 3-phase,3 wire load circuits.The current coils of two wattmeters are inserted in any two lines and pressure coil is connected from its own current coil to the line without a current coil. Let V1,V2,V3 and I1,I2,I3 be the voltages and currents … Read more
Measurement of Three Phase power:Three wattmeter method Wattmeter is a devices in AC circuit used for power measurement. Wattmeter is a devices which consists of two coils called Current coil(CC) and pressure coil (PC).Current coil is a low resistance coil which is inserted in series with line carrying current to be measured and pressure coil … Read more
Magnetic circuits Definition The closed path followed by the magnetic flux is magnetic circuit.All electric power machinery such as generator,transformer,motors depend for their operation on the magnetic circuits. A magnetic circuit consists of a structure composed for the most of high permeability magnetic material.The core is assumed to be composed of magnetic material whose permeability … Read more