
Convert 28.8 khJ into watt hour.
A. \[8\times {{10}^{-3}}\]kWh
B. 8 kWh
C. \[8\times {{10}^{3}}\] kWh
D. None of these
Answer
563.7k+ views
Hint: Energy, as most physical quantities can be represented and measured in many different units. As all these representations represent the same quantity interconverted to one another. The conversion rate of Joule to Watt Hour is given below
Formula Used:
\[1Wh=3600J\]
\[1Wh={{10}^{-3}}kWh\]
Complete answer:
Energy, as most physical quantities, can be represented and measured in many different units. As all these representations represent the same quantity interconverted to one another. Two of the most used units of energy are watt-hour and Joule. To convert one unit to another we should know the conversion rate.
Coming to the question we have to convert kilojoules to kilowatt-hours. We know that
\[1Wh=3600J\]
For using this conversion, we need the energy in Joules.
\[28.8khJ=28.8\times {{10}^{3}}J\]
And we also know that
\[1Wh={{10}^{-3}}kWh\]
So putting all these together. The energy in kilowatt-hour would be
\[E=\dfrac{28.8\times {{10}^{3}}}{3.6\times {{10}^{6}}}\]
\[\Rightarrow E=8\times {{10}^{-3}}kWh\]
So, the energy in watt-hour would be \[8\times {{10}^{-3}}kWh\]
Therefore, Option A is the correct one.
Note:
The SI unit of energy is Joule and is written as J. This unit was named in honour of James Prescott Joule. Joule is also the standard unit of Work Done and can be defined as the work done by a force of magnitude 1N acting through a meter of 1 meter. 1 Joule is equal to \[{{10}^{7}}\]ergs which is a unit used to measure a small amount of work done.
Formula Used:
\[1Wh=3600J\]
\[1Wh={{10}^{-3}}kWh\]
Complete answer:
Energy, as most physical quantities, can be represented and measured in many different units. As all these representations represent the same quantity interconverted to one another. Two of the most used units of energy are watt-hour and Joule. To convert one unit to another we should know the conversion rate.
Coming to the question we have to convert kilojoules to kilowatt-hours. We know that
\[1Wh=3600J\]
For using this conversion, we need the energy in Joules.
\[28.8khJ=28.8\times {{10}^{3}}J\]
And we also know that
\[1Wh={{10}^{-3}}kWh\]
So putting all these together. The energy in kilowatt-hour would be
\[E=\dfrac{28.8\times {{10}^{3}}}{3.6\times {{10}^{6}}}\]
\[\Rightarrow E=8\times {{10}^{-3}}kWh\]
So, the energy in watt-hour would be \[8\times {{10}^{-3}}kWh\]
Therefore, Option A is the correct one.
Note:
The SI unit of energy is Joule and is written as J. This unit was named in honour of James Prescott Joule. Joule is also the standard unit of Work Done and can be defined as the work done by a force of magnitude 1N acting through a meter of 1 meter. 1 Joule is equal to \[{{10}^{7}}\]ergs which is a unit used to measure a small amount of work done.
Recently Updated Pages
Basicity of sulphurous acid and sulphuric acid are

Who is the Indian to beat the computers in Mathematical Wizardry?

Where is Himalayan Mountaineering Institute Located?

Which Country is Called "The Land of Festivals"?

Who is the Tennis Player Known as 'King of Clay'?

Who Wrote James Bond? Novel vs. Video Game Facts

Trending doubts
What is meant by exothermic and endothermic reactions class 11 chemistry CBSE

Define electric capacity Derive an expression for the class 11 physics CBSE

Which type of resource is iron ore A Renewable B Biotic class 11 social science CBSE

10 examples of friction in our daily life

Differentiate between an exothermic and an endothermic class 11 chemistry CBSE

1 Quintal is equal to a 110 kg b 10 kg c 100kg d 1000 class 11 physics CBSE

