वाट

वाट (चिं: W) शक्तिया एस आइ युनिट ख। १ वाट शक्ति १ जुल उर्जा प्रति सेकेन्ड बराबर जुइ। अतः, थ्व उर्जा परिवर्तनयात दानास्वइगु युनिट ख।

छम्ह मनु स्वाने गयाच्वनि बिले थ्यं-मथ्यं औसत २०० वाटया ज्या यानाच्वनि। छगू औसत अटोमोबाइल इञ्जिनं क्रुज यानाच्वनि बिले करिब २५,००० वाटया मेक्यानिकल इनर्जी पिकाइ। छगू छेंय् इन्क्यान्डेस्सेन्ट लाइट बल्ब छ्य्‌लि बिले औसत उर्जा २५ निसें १०० वाटय् छ्यलि धाःसा कम्प्याक्ट फ्लुरोस्सेन्ट लाइटय् ५ निसें ३० वाटया दरय् उर्जा छ्यलि।

परिभाषा

One watt is the rate at which work is done when an object is moving at one meter per second against a force of one newton.

$1~{\rm {{W}=1~{\dfrac {\rm {J}}{\rm {s}}}=1~{\dfrac {\rm {{kg}\cdot {\rm {m^{2}}}}}{\rm {s^{3}}}}=1~{\dfrac {\rm {N\cdot m}}{\rm {s}}}}}$.

By the definition of the units of ampere and volt, work is done at a rate of one watt when one ampere flows through a potential difference of one volt.

Origin and adoption as an SI unit

The watt is named after James Watt for his contributions to the development of the steam engine, and was adopted by the Second Congress of the British Association for the Advancement of Science in 1889 and by the 11th General Conference on Weights and Measures in 1960 as the unit of power incorporated in the International System of Units (or "SI").

This SI unit is named after James Watt. As with every SI unit whose name is derived from the proper name of a person, the first letter of its symbol is upper case (W). When an SI unit is spelled out in English, it should always begin with a lower case letter (watt), except where any word would be capitalized, such as at the beginning of a sentence or in capitalized material such as a title. Note that "degree Celsius" conforms to this rule because the "d" is lowercase. —Based on The International System of Units, section 5.2.

Derived and qualified units for power distribution

Microwatt

The microwatt (symbol:μW) is equal to one millionth (10^-6) of a watt.

Milliwatt

The milliwatt (symbol:mW) is equal to one thousandth (10^-3) of a watt. A typical laser pointer might output 5 milliwatts.

Kilowatt

The kilowatt (symbol: kW), equal to one thousand watts, is typically used to state the power output of engines and the power consumption of tools and machines. A kilowatt is approximately equivalent to 1.34 horsepower. An electric heater with one heating-element might use 1 kilowatt.

Megawatt

The megawatt (symbol: MW) is equal to one million (10⁶) watts.

Many things can sustain the transfer or consumption of energy on this scale; some of these events or entities include: lightning strikes, large electric motors, naval craft (such as aircraft carriers and submarines), engineering hardware, and some scientific research equipment (such as the supercollider and large lasers). A large residential or retail building may consume several megawatts in electric power and heating energy.

The productive capacity of electrical generators operated by utility companies is often measured in MW. Modern high-powered diesel-electric railroad locomotives typically have a peak power output of 3 to 5 MW, whereas U.S. nuclear power plants have net summer capacities between about 500 and 1300 MW.

According to the Oxford English Dictionary, the earliest citing for "megawatt" is a reference in the 1900 Webster's International Dictionary of English Language. The OED also says "megawatt" appeared in a 28 November, 1847, article in Science (506:2).

Gigawatt

The gigawatt (symbol: GW) is equal to one billion (10⁹) watts. This unit is sometimes used with large power plants or power grids.

Terawatt

The terawatt (symbol: TW) is equal to one trillion (10¹²) watts. The average Power usage by humans (about 15 TW) is commonly measured in these units. The most powerful lasers from the mid 1960s to the mid 1990s produced power in terawatts, but only for nanoseconds.

Electrical and thermal

In the electric power industry, Megawatt electrical (abbreviation: MW_e or MWe) is a term that refers to electric power, while megawatt thermal (abbreviations: MW_t, MW_th, MWt, or MWth) refers to thermal power produced. Other SI prefixes are sometimes used, for example gigawatt electrical (GW_e).

For example, the Embalse nuclear power plant in Argentina uses a fission reactor to generate 2109 MW_t of heat, which creates steam to drive a turbine, which generates 648 MW_e of electricity. The difference is heat lost to the surroundings.

Confusion of watts and watt-hours

Power and energy are frequently confused in the general media. Power is the rate at which energy is used (or generated). A watt is one joule of energy per second. For example, if a 100 watt light bulb is turned on for one hour, the energy used is 100 watt-hours or 0.1 kilowatt-hour, or 360,000 joules. This same quantity of energy would light a 40-watt bulb for 2.5 hours. A power station would be rated in watts, but its annual energy sales would be in watt-hours (or kilowatt-hours or megawatt-hours). A kilowatt-hour is the amount of energy equivalent to a steady power of 1 kilowatt running for 1 hour, or 3.6 megajoules.

स्वयादिसँ

उर्जा दबू

• Volt-ampere
• Conversion of units
• James Watt
• Declared net capacity (power plants)
• Orders of magnitude (power)
• Power factor
• Root mean square (RMS)
• Watt balance
• Watt-hour
• Wattmeter

पिनेया स्वापू

• Nelson, Robert A., "The International System of Units Its History and Use in Science and Industry". Via Satellite, February 2000.