Question

One kilo watt hour equals ______ $J$ (joules) of energy.

• A. $1.2$ $\times$ ${10}^6$
• B. $2.4$ $\times$ ${10}^6$
• C. $3.6$ $\times$ ${10}^6$
• D. $4.8$ $\times$ ${10}^6$

Answer 1

The correct option is C $3.6$ $\times$ ${10}^6$

1 kilo watt (kW) = $1000J{s}^{-1}$
and 1 hour = $3600s$.

$⟹$ 1 kW h = $1000J{s}^{-1}$ $\times$ $3600s$
= $3600000J$
= $36\times {10}^{5}J$
= $3.6\times {10}^{6}J$.