How many kilowatt hours are used to light a 100 watt light bulb for 1 hour?

Answer 1

Remember that 1 kW = 1000 W

So 100 / 1000 = 0.1

100 W = 0.1 kW

You take the power - the wattage of the lamp, and multiply with how long it is lit. A 100 W bulb - 0.1 kW - will use 0.1 kWh in one hour. Or 1 kWh in 10 hours. Or 10 kWh in 100 hours.

Answer 2

Depends on the power - the wattage of the lamp, and how long it is lit.

You take the power - the wattage of the lamp, and multiply with how long it is lit. A 100 W bulb - 0.1 kW - will use 0.1 kWh in one hour. Or 1 kWh in 10 hours. Or 10 kWh in 100 hours.

Answer 3

60 watts is 0.06 kW, so the bulb uses 0.06 kilowatt-hours of energy in one hour, or 0.6 kilowatt-hours in ten hours, or 6 kWh in 100 hours, etc.

Note:

The questioner is confusing 'power' with 'energy'. You do not 'consume' power; you consume energy. Power is simply a rate, which tells you how much energy you are consuming over a given period of time. So, as explained, below, you should be asking, 'How many kilowatt hours' does a 60-W lamp use per hour?'

A watt is a unit of power, whereas a joule is a unit of energy. So a watt is equivalent to (and a special name for) a 'joule per second'. However, electricity utility companies normally measure energy is a larger unit called a 'kilowatt hour' (energy is equivalent to power multiplied by time). Since 60 W is equivalent to 0.06 kilowatts, your 60-W lamp is consuming 0.06 kilowatt hours of energy over a period of one hour.

1 kilowatt = 1000 Watt

The power of the lamp is 60 W. 60 / 1000 = 0.06 kW

So for one hour: 0.06 x 1 = 0.06 kWh