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Electric Field Intensity
Published in Ahmad Shahid Khan, Saurabh Kumar Mukerji, Electromagnetic Fields, 2020
Ahmad Shahid Khan, Saurabh Kumar Mukerji
In connection with the electricity, the terms power, voltage, and current are understood even by a layperson. The power is measured in watts (W), the voltage in volts (V), and the current in amperes (A). The (instantaneous) electric power (w) is the product of voltage (v) and current (i) (i.e. w = vi). If a device consumes 100 W of electric power and operates at 100 V it will draw a current of 1A. As 1A current transports 1C of charge/sec through the conductor, thus 1C is the charge transported through the device in 1 second. Thus the force between two charge concentrations of 1C each, at points 1 m apart, obtained by applying Coulomb’s law (Equation 5.3) comes out to be 9 × 109 Newtons or about 1.01 million tons, which is tremendously large. Since the two charges are of the same polarity this force is repulsive. The two charges will move apart from each other even if they have to rip themselves out of solid steel to do so. It may be noted that nature never allows concentration of 1C charge at one point and there is never much departure from electrical neutrality at a given point in a conductor.
Electricity and Utility Industry
Published in Roy L. Nersesian, Energy Economics, 2016
The terms electricity and electrical energy are used interchangeably even though they are technically quite different. Generators cannot make electricity (technically electrical energy) because electricity similar to temperature is a property of matter. An electricity generator “pumps” an electrical charge back and forth inside a wire 60 times per second, and electromagnetic fields created around the wire are what is known as electrical power. Electrical power flowing through a motor, heater, or light bulb over time becomes electrical energy that turns the rotor and warms or lights a room. Electrical energy is electrical power performing some function over time. One hundred watts can light a 100 W bulb—that is power. Keeping the bulb lit for 1 hour is 100 Wh—that is energy. A watt is a measure of “capacity” to deliver power, whereas watt-hour is the amount of energy or power delivered over time. Power is what can be delivered at a moment in time, and energy is the integral of power over time. Kilowatt-hours (kWh) charged in an electricity bill from the local utility represent the electrical energy consumed by the customer.
Basic Concepts about Electricity
Published in Dorothy Gerring, Renewable Energy Systems for Building Designers, 2023
Energy is power multiplied by the time you used it for, so energy is measured in watt hours. The symbol is Wh; 1000 watt hours = 1 kilowatt hour and the symbol for kilowatt hour is kWh. If you have a utility bill, it will charge you for how many kilowatt hours you used in the month.
Advanced thermal environment and energy consumption calculation over time using combined energy simulation, computational fluid dynamics, and heat source model
Published in Journal of Building Performance Simulation, 2021
Tatsuhiro Yamamoto, Akihito Ozaki, Keigo Aratsu
Power consumption (P [W]), current (I [A]), and voltage (v [V]) can be measured using a wattmeter. Power consumption can be calculated from the following equation by incorporating the power factor supplied by the manufacturer of the AC, which is the value indicating the efficiency of the AC power (i.e. the ratio of the effective power to the apparent power): Using Equations (2)–(8), the COP can be calculated according to the measured value in Equation (1).
Contributions of vehicle dynamics to the energy efficient operation of road and rail vehicles
Published in Vehicle System Dynamics, 2021
Jenny Jerrelind, Paul Allen, Patrick Gruber, Mats Berg, Lars Drugge
Aligned with published research works, this review will use energy and power as relevant measures for energy consumption, energy/power savings and energy efficiency. Energy is commonly measured in Joule (J) and watt-hour (Wh) and is the total quantity of work done without reference to the duration of the work. Power is the rate of consuming or producing energy and is measured in J/s or watt (W).