Technologically important powers that are measured in femtowatts are typically found in references to radio and radar receivers. For example, meaningful FM tuner performance figures for sensitivity, quieting and signal-to-noise require that the RF energy applied to the antenna input be specified. These input levels are often stated in dBf decibels referenced to 1 femtowatt. This is 0. Technologically important powers that are measured in picowatts are typically used in reference to radio and radar receivers, acoustics and in the science of radio astronomy.
One picowatt is the international standard reference value of sound power when this quantity is expressed as a level in decibels. Important powers that are measured in nanowatts are also typically used in reference to radio and radar receivers. Important powers that are measured in microwatts are typically stated in medical instrumentation systems such as the EEG and the ECG , in a wide variety of scientific and engineering instruments and also in reference to radio and radar receivers.
Compact solar cells for devices such as calculators and watches are typically measured in microwatts. A typical laser pointer outputs about five milliwatts of light power, whereas a typical hearing aid for people uses less than one milliwatt. The kilowatt kW is equal to one thousand 10 3 watts.
This unit is typically used to express the output power of engines and the power of electric motors, tools, machines, and heaters.
It is also a common unit used to express the electromagnetic power output of broadcast radio and television transmitters. One kilowatt is approximately equal to 1. A small electric heater with one heating element can use 1.
What do watt and kWh mean?
The average electric power consumption of a household in the United States is about one kilowatt. A surface area of one square meter on Earth receives typically about one kilowatt of sunlight from the sun the solar irradiance on a clear day at mid day, close to the equator. The megawatt MW is equal to one million 10 6 watts. Many events or machines produce or sustain the conversion of energy on this scale, including large electric motors; large warships such as aircraft carriers, cruisers, and submarines; large server farms or data centers ; and some scientific research equipment, such as supercolliders , and the output pulses of very large lasers.
- DA PSU GAMING 400 WATT.
- Or So It Seems .... The Stupid Minivan and More Tales of Midlife Madness;
- Poems of Hope, Inspiration & Power;
- Navigation menu.
- Promoting Conflict or Peace through Identity.
A large residential or commercial building may use several megawatts in electric power and heat. The OED also states that megawatt appeared in a 28 November article in the journal Science This unit is often used for large power plants or power grids. For example, by the end of power shortages in China's Shanxi province were expected to increase to 5—6 GW  and the installed capacity of wind power in Germany was The terawatt TW is equal to one trillion 10 12 watts. The total power used by humans worldwide is commonly measured in terawatts. The most powerful lasers from the mids to the mids produced power in terawatts, but only for nanosecond time frames.
The average lightning strike peaks at 1 terawatt, but these strikes only last for 30 microseconds. One such laser is the Lawrence Livermore's Nova laser , which achieved a power output of 1. The duration of the pulse was roughly 0. Based on the average total solar irradiance  of 1. In the electric power industry , megawatt electrical MWe  or MW e  refers by convention to the electric power produced by a generator, while megawatt thermal or thermal megawatt  MWt, MW t , or MWth, MW th refers to thermal power produced by the plant.
Other SI prefixes are sometimes used, for example gigawatt electrical GW e. The International Bureau of Weights and Measures , which maintains the SI-standard, states that further information about a quantity should not be attached to the unit symbol but instead to the quantity symbol i. When describing alternating current AC electricity, another distinction is made between the watt and the volt-ampere. While these units are equivalent for simple resistive circuits , they differ when loads exhibit electrical reactance. Radio stations usually report the power of their transmitters in units of watts, referring to the effective radiated power.
This refers to the power that a half-wave dipole antenna would need to radiate to match the intensity of the transmitter's main lobe.
The terms power and energy are frequently confused. Power is the rate at which energy is generated or consumed and hence is measured in units e.
Keep Exploring Britannica
Related questions How much power does an electric car use? How is gas consumption calculated? How to reduce the power consumption of my refrigerator and freezer? Energy labels: what is new in ?
DA PSU GAMING 400 WATT
In electrical…. Horsepower , the common unit of power; i. In the British Imperial System, one horsepower equals 33, foot-pounds of work per minute—that is, the power necessary to lift a total mass of 33, pounds one foot in one minute. This value was adopted by…. Ampere , unit of electric current in the International System of Units SI , used by both scientists and technologists. In the General Conference on Weights and Measures CGPM agreed that on May 20, , the ampere would henceforth be defined such that the elementary charge would be equal to 1.
History at your fingertips. Sign up here to see what happened On This Day , every day in your inbox! By signing up, you agree to our Privacy Notice. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox.
watt - Wiktionary
Help us improve this article! Contact our editors with your feedback. Edit Mode. Tips For Editing.