Answer
Verified
396k+ views
Hint: First, understand what power is. Define power and write the formula for it. In simple words power is nothing but work done per unit time. Convert the mathematical formula of power into basic units in the MKS system. Now, define 1 unit of power in the S.I. system. Power can also be defined as energy per unit time.
Complete answer:
The International System of Units (SI) is the modern form of the metric system. It is the only system of measurement with official status in nearly every country in the world. It comprises a coherent system of units of measurement starting with seven base units.
The work done per unit time is referred to as power. Sometimes Power is also defined as the energy consumed per unit time or rate of consumption of energy.
Therefore,
$\text{Power =}\dfrac{\text{Workdone}}{\text{Time}}\text{=}\dfrac{\text{Energy consumed }}{\text{Time}}$
If $W$is the work done in time t then power is given as
$P=\dfrac{W}{t}$
In order to get S.I. unit of power, the units of work done and time must be in S.I. system
Thus, if work done is in joules and time is in seconds then S.I. unit of power is given as
S.I. unit of power $\text{= }\dfrac{\text{Joule}}{\text{Second}}=Watt$
Thus, S.I. the unit of power is Joule per second or Watt.
Definition of 1 Watt:
If 1 Joule of work is done in 1 second then we say that 1 Watt of power is consumed.
Additional Information:
Units used to measure different quantities vary from place to place. So to have a uniformity in units a system called ‘The International System of Units’ (abbreviated as SI) is used.
There are seven basic units defined in the SI system:
Length – meter $\left( m \right)$
Time – second $\left( s \right)$
Amount of substance – mole $\left( mole \right)$
Electric current – ampere $\left( A \right)$
Temperature – kelvin $\left( K \right)$
Luminous intensity – candela $\left( cd \right)$
Mass – kilogram $\left( kg \right)$
Power is also expressed in other units like kWh (kilowatt hour), hp (horsepower), ergs per second, milliwatt, etc.
$1\text{ horsepower }=\text{ }745.7\text{ }Watts$
Note:
It is not necessary to memorize units. Only understand the concept of power from that you can deduce the formula and units. Do not get confused with the S.I. unit of power since usually it is expressed in many units.
Power can also be written as $\text{P = Vx I = Volt x Amp}$
Unit of power can also be deduced by the following method.
$\begin{align}
& P=V\times I \\
& 1volt\times 1Amp=\dfrac{1J}{1C}\times \dfrac{1C}{1s} \\
& \dfrac{1J}{1s}=W(watt) \\
\end{align}$
The S.I. unit of power is $W$.
Complete answer:
The International System of Units (SI) is the modern form of the metric system. It is the only system of measurement with official status in nearly every country in the world. It comprises a coherent system of units of measurement starting with seven base units.
The work done per unit time is referred to as power. Sometimes Power is also defined as the energy consumed per unit time or rate of consumption of energy.
Therefore,
$\text{Power =}\dfrac{\text{Workdone}}{\text{Time}}\text{=}\dfrac{\text{Energy consumed }}{\text{Time}}$
If $W$is the work done in time t then power is given as
$P=\dfrac{W}{t}$
In order to get S.I. unit of power, the units of work done and time must be in S.I. system
Thus, if work done is in joules and time is in seconds then S.I. unit of power is given as
S.I. unit of power $\text{= }\dfrac{\text{Joule}}{\text{Second}}=Watt$
Thus, S.I. the unit of power is Joule per second or Watt.
Definition of 1 Watt:
If 1 Joule of work is done in 1 second then we say that 1 Watt of power is consumed.
Additional Information:
Units used to measure different quantities vary from place to place. So to have a uniformity in units a system called ‘The International System of Units’ (abbreviated as SI) is used.
There are seven basic units defined in the SI system:
Length – meter $\left( m \right)$
Time – second $\left( s \right)$
Amount of substance – mole $\left( mole \right)$
Electric current – ampere $\left( A \right)$
Temperature – kelvin $\left( K \right)$
Luminous intensity – candela $\left( cd \right)$
Mass – kilogram $\left( kg \right)$
Power is also expressed in other units like kWh (kilowatt hour), hp (horsepower), ergs per second, milliwatt, etc.
$1\text{ horsepower }=\text{ }745.7\text{ }Watts$
Note:
It is not necessary to memorize units. Only understand the concept of power from that you can deduce the formula and units. Do not get confused with the S.I. unit of power since usually it is expressed in many units.
Power can also be written as $\text{P = Vx I = Volt x Amp}$
Unit of power can also be deduced by the following method.
$\begin{align}
& P=V\times I \\
& 1volt\times 1Amp=\dfrac{1J}{1C}\times \dfrac{1C}{1s} \\
& \dfrac{1J}{1s}=W(watt) \\
\end{align}$
The S.I. unit of power is $W$.
Recently Updated Pages
In a flask the weight ratio of CH4g and SO2g at 298 class 11 chemistry CBSE
In a flask colourless N2O4 is in equilibrium with brown class 11 chemistry CBSE
In a first order reaction the concentration of the class 11 chemistry CBSE
In a first order reaction the concentration of the class 11 chemistry CBSE
In a fermentation tank molasses solution is mixed with class 11 chemistry CBSE
In a face centred cubic unit cell what is the volume class 11 chemistry CBSE
Trending doubts
Which are the Top 10 Largest Countries of the World?
Difference Between Plant Cell and Animal Cell
Give 10 examples for herbs , shrubs , climbers , creepers
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
Write a letter to the principal requesting him to grant class 10 english CBSE
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
What is the full form of AD a After death b Anno domini class 6 social science CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
Name 10 Living and Non living things class 9 biology CBSE