Question

The number of joules contained in 1kWh is_____

• A. $36\times {10}^2$
• B. $36\times {10}^3$
• C. $36\times {10}^4$
• D. $3.6\times {10}^6$

Answer 1

Answer: (D)

The correct option is D $3.6\times {10}^6$
The kilowatt hour is a unit of energy equal to 3.6 megajoules. If the energy is being transmitted or used at a constant rate over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.

Let energy is used as 1J/s. For an hour or 3600 sec. Then total energy used is 3600J. And kWh means 1000$\times$3600.

Which gives $3.6\times {10}^6$.