Question

$1\text{kWh}$ is equal to

• A. $3.6\text{kJ}$
• B. $36\text{kJ}$
• C. $3.6\text{mJ}$
• D. $3.6\text{MJ}$

Answer 1

The correct option is D

$3.6\text{MJ}$

Step 1: Used Formulas:

The following conversion formulas are used:

$1\text{kW}={10}^3\text{W}$

$1\text{h}=3600\text{s}$

$1\text{Ws}=1\text{Watt-s}=1\text{J}$

$1\text{MJ}={10}^6\text{J}$

Step 2: Conversion:

$1\text{kWh}=\left(1\text{kW}\times \frac{{10}^3\text{W}}{1\text{kW}}\right)\times \left(1\text{h}\times \frac{3600\text{s}}{1\text{h}}\right)$

$=\left({10}^3\times 3600\text{Ws}\right)\times \frac{1\text{J}}{1\text{Ws}}$

$=3.6\times {10}^6\text{J}$

$\text{=}\left(3.6\times {10}^6\text{J}\right)\times \left(\frac{1\text{MJ}}{{10}^6\text{J}}\right)$

$=3.6\text{MJ}$

Hence, the correct option is (D).