Question

The number of joules that is equal in value to 1 kWh is.

• A. $3.6\times {10}^8$
• B. $0.36\times {10}^4$
• C. $3.6\times {10}^5$
• D. $3.6\times {10}^6$

Answer 1

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

1 kWh is equal to 3.6 $\times$ 10${}^6$

1 Watt-sec is a Joule a watt expended for a second.

Because there’s 3600 seconds in an hour,

then 3600 Ws = 1 Wh = 3600 Joules = 3.6 kJ

so 1000 Wh = 1 kWh = 1000 $\times$ 3.6 kJ = 3.6 MJ = 3.6 $\times$ 10${}^6$