300w uses 7.2 kilowatt-hours of electricity a day. In order to allow more friends to actually convert the electricity consumption of electrical appliances, here I will give you a popular science.
One: the problem of electric power
Electric power is also called "electrical power", which represents the amount of work done by the current per unit time in a conductive circuit. We use "P" to represent power, and its standard unit is "watt", which can be said to be "watt" for convenience, and the symbol is "W". For example, 20W means that the power is 20 watts.
In fact, power not only has the basic standard unit of "watt", but also uses the unit of "kilowatt" to express large power. The symbol of kilowatt is "KW". The conversion formula between kilowatt and watt is as follows:
1000 watts (W) = 1 kilowatt (KW). In real life, some large-power electrical appliances in the family, such as 1000W air conditioners, can be directly written as "1KW".
We usually use a power meter to measure the power of the electricity.
Two: The problem of kilowatt-hours
Although "kilowatt-hour" looks a bit like power "kilowatt", they are two different physical concepts. "Kilowatt-hour" refers to the actual energy consumed by an electrical appliance with a power of one kilowatt for one hour.
So we can see from its definition that kilowatt-hour (KWh) is the result of multiplying power (KW) and time (h), that is: 1 kilowatt-hour (KWh) = 1 kilowatt (KW) × 1 hour (h) .
The "degree" we often refer to now means kilowatt-hours. We can directly understand that 1 kilowatt-hour = 1 kilowatt-hour of electricity, and 33 kilowatt-hours = 33 kilowatt-hours of electricity.
So based on the above knowledge, we can know that the calculation method of the daily electricity consumption of 300W electrical appliances is: first convert the power W into KW, that is, 300W/1000=0.3 kilowatts; then convert it into kilowatt hours, that is, 0.3 kilowatts× 1 hour = 0.3 kWh, which is 0.3 kWh.
One hour uses 0.3 kilowatt-hours of electricity, so the electricity consumption for 24 hours a day is 0.3×24=7.2 kilowatt-hours of electricity. So 300w uses 7.2 kilowatt-hours of electricity a day.