One kilowatt hour (kWh) is a unit of energy. It represents the amount of energy consumed or produced by a device with a power of one kilowatt (kW) in a time period of one hour.

Option 1: 36 x 10^3 joules. This option suggests that one kilowatt hour is equal to 36 multiplied by 10^3 joules. However, this is incorrect as it does not represent the accurate conversion.

Option 2: 36 * 10^5 joules. This option correctly states that one kilowatt hour is equal to 36 multiplied by 10^5 joules. This conversion is accurate and matches the standard conversion from kilowatt hours to joules.

Option 3: 10^3 joules. This option suggests that one kilowatt hour is equal to 10^3 joules. However, this is incorrect as it does not account for the multiplier of 36.

Option 4: 10^5 joules. This option suggests that one kilowatt hour is equal to 10^5 joules. However, this is incorrect as it does not account for the multiplier of 36.

Therefore, the correct answer is option