Author: John Mulindi
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Basic Electric Circuits Questions and Answers
The answers have been provided towards the end of these questions: Answers: You may also read:
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Single-phase vs. Three-phase Power Systems
Thomas A. Edison’s work on electric light led to the concept of a centrally located power station with distributed electric power for lighting. Edison’s work on dc systems expanded with the development of three-wire 220 V dc systems but transmission distances and loads continued to grow, voltage problems were encountered but with the development of…
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Electrical Motors
Motors convert electrical energy into rotational mechanical energy. Electrical motors are used to power many devices used in everyday life like refrigerators, washing machines, elevators, ventilation fans etc. Industrial applications include bulk material handling pumps, rock crushers, machinery operations, compressors, etc. Basic construction of an electrical motor An electrical motor consists of a stationary part…
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Power Measurements in DC Circuits
Measurement of electric power is essential in both commercial industrial applications and domestic applications. Prior estimation and subsequent measurements of instantaneous and peak power demands of any installation are mandatory for design, operation and maintenance of the electric power supply network feeding it. How Power Measurements in DC circuits are done using an Ammeter and…
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Basics of Radio Frequency (RF) and Wireless Communication Systems
Radio frequency (RF) is any frequency within the electromagnetic spectrum associated with radio-wave propagation. When an RF current (input signal) is supplied to an antenna, an electromagnetic field is created that is then able to propagate through the space. RF field propagation technology is used in many wireless technologies like: 1. Remote Sensing: Telemetry Tracking…
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Microwave Tubes
It was discovered in 1939 that a toroidal cavity made of conductive material called a cavity resonator surrounding an electron beam of oscillating intensity could extract power from the beam without intercepting the beam itself. The oscillating electric and magnetic fields associated with the beam ‘’echoed’’ inside the cavity, in a manner similar to the…
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Optoelectronics
Optoelectronics deals with the study of all the electrically driven light-emitting devices, all devices which produce electrical effects when exposed to light, and all methods of conducting light through fixed pathways. Photometry units When a current is passed through a light source, a portion of the power dissipated appears in the form of light radiated…
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What is the Controller?
A controller is a device that generates an output signal based on the input signal it receives. The input signal is actually an error signal, which is the difference between the measured variable, and the desired value, or setpoint. The input error signal represents the amount of deviation between where the process system is actually…
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The Operation of a Temperature Control System for lubricating oil
Lubricating oil reduces friction between moving parts and also removes heat from the components. As a result, the oil becomes hot. This heat is removed from the lubricating oil by a cooler to prevent both the breakdown of the oil and damage to the mechanical components it serves. The lubricating oil cooler consists of a…