Power transformers are critical and costly assets in the electric power system. They are one of the most important electric apparatuses for providing reliable energy flow. They also constitute one of the largest investments in a utility system or in an industrial complex. For this reason, transformer condition assessment and management are a high priority. […]
An oil-filled transformer insulation system consists of insulating oil and cellulose (paper) materials. Under normal use, transformer insulation deteriorates and generates certain combustible and noncombustible gases. This effect becomes more pronounced when the transformer insulation is exposed to higher temperatures. When cellulose insulation (i.e., winding insulation) is overheated to temperatures as low as 140°C, carbon
The power factor test and dissipation factor test are considered to be synonymous because they both refer to the AC dielectric loss test. PF and DF are but two of the several measurable characteristics that can be obtained from an AC dielectric loss test used for evaluating the condition of the insulation system. Both of
In this article, I shall be discussing the existing underground cable fault location methods. Faults in a cable may vary widely, and similar faults may show different symptoms depending upon the cable type, operating voltage, soil condition, and so on. Faults can be considered to be shorts, opens, or nonlinear. A short is defined as
There are large number of lithium cells out there. Many of them look similar, but their specifications and ratings are what set them apart. There’s a very long list of lithium-ion battery specifications. Here we will look at the most important lithium ion battery specifications. Lithium Ion Battery Specifications Capacity The capacity of a cell
A lithium-ion cell is composed of four main parts: The cathode varies between different types of cells but is always a lithium compound mixed with other materials. The anode is almost always graphite, and sometimes includes trace amounts of other elements. The electrolyte is generally an organic compound containing lithium salts to transfer lithium ions. The porous
The demand for electrical energy is increasing day by day. So a boom in the consumption of electrical energy has been seen in the last few decades. It is the very reason for the growth in the field of electrical engineering. Due to this growth, carriers in this field are increasing day by day. Almost
Basic Electrical Questions and Answers PDF Download Read More »
1. A synchrotransmitter consists of a (a) salient pole rotor winding excited by an ac supply and a 3-phase balanced rotor winding. (b) three phase balanced stator winding excited by a three phase balanced ac signal and rotor connected to a dc voltage source. (c) salient pole, rotor winding excited by a dc signal. (d)
Instrumentation Multiple Choice Questions Answers Read More »
1. A recorder (a) is an indicating instrument which displays a time varying signal. (b) is a device whose function is to record the value of quantity as it is being measured. (c) records electrical and non-electrical quantities as a function of time or relates two signals to each other. (d) both (b) and (c).
Instrumentation Multiple Choice Questions Answers PDF Read More »
1. A CRO screen has 10 divisions on the horizontal scale. If a voltage signal 5 sin (314 t + 45°) is examined with a line base setting of 5 ms/division, the number of cycles of signal displayed on the screen will be (a) 0.5 cycle (b) 2.5 cycles (c) 5 cycles. (d) 10 cycles.
Electrical and Electronics Measurement Mcq Questions Read More »