There’s no battery in my laptop, I’m operating it using straight AC power. I shut down my laptop, but I do not switch the outlet off. OR I turn off my radio or TV-set, but leave the outlet on. Is electrical power being consumed? Why?

When you shutdown your laptop, it needs no power, but the power supply does not know that, so it continues to convert the AC power to ~20 V DC. So, although there is no power being withdrawn from the power supply, some power is being "wasted" in the conversion process, but it is very small (<1W).

In case of TV, it is more involved, because the TV is actively consuming power to run the essential electronics to accept the remote signals to turn the TV on or to activate the "ON" timer. This power is called as standby power. For most modern LCD/LED TVs, this is around 1-2 W.

See question on Quora

I like to blog about various topics ranging from education in IITs to social issues in India and US. All opinions and views presented here are my own and not of my employer.

Leave a Reply