Which statement is true about the relationship between kilowatt-hours and joules?

Which statement is true about the relationship between kilowatt-hours and joules?

• A. 1 kWh is 3600 J
• B. 1 kWh is 3,600,000 J
• C. 1 kWh is 3,600 J
• D. 1 kWh is 0.0036 J

Answer: (B)

A kilowatt-hour is a unit of energy, not power, and it expresses how much work is done when a rate of one kilowatt operates for a full hour. To convert to joules, use that 1 kilowatt equals 1000 watts and 1 hour equals 3600 seconds. Multiply: 1000 W × 3600 s = 3,600,000 J. So 1 kWh equals 3,600,000 joules (3.6 MJ). The other options mix up the time or the thousand factor—for example, 3600 J would be 1 Wh, not 1 kWh, and 0.0036 J is far too small.

A kilowatt-hour is a unit of energy, not power, and it expresses how much work is done when a rate of one kilowatt operates for a full hour. To convert to joules, use that 1 kilowatt equals 1000 watts and 1 hour equals 3600 seconds. Multiply: 1000 W × 3600 s = 3,600,000 J. So 1 kWh equals 3,600,000 joules (3.6 MJ). The other options mix up the time or the thousand factor—for example, 3600 J would be 1 Wh, not 1 kWh, and 0.0036 J is far too small.