Yes. Assuming you're talking about CRT monitors, the monitor takes up a large percentage of the total power consumed by the computer system, from something like 60 Watts for a small monitor to more than 100W for a large one.
However, frequently switching on and off puts a lot of stress on certain components inside the monitor and may shorten its life.
All modern monitors are made capable of going into a standby mode where they consume only a small amount of power when the computer has not received a fresh command from the user for some time. This is done when you set the power options in Windows.
Whether it's worth switching off for 5 or 10 minutes depends on how often you do it. If you leave it only a couple of times a day, the saving in electricity will be quite small and IMO not worth the extra stress on your monitor. Better to set the power settings properly.
Oh yes it does use a major amount of power .
The best thing is when we are not using it should not be on .
There was an article in the newspapers a few days back regarding this that many people abroad do not switch of there monitors after working hours and think that the screensaver or standby will be the same.
But its not so as proved because monitors use the main amount of power and so to save electricity its best to swithc them off.
I usually directly switch off the monitor when i'm not around for a long period of time rather than letting it go into standby.
__________________
From the body of one guilty deed a thousand ghostly fears and haunting thoughts proceed !
an lcd monitor will consume anything upto 40 W... 15" lcd monitors consume around 25W... 17 inchers are around 35 W and 19 inchers are around 40-45 W.....
dudes. what setting should I keep my monitor at? 5 minutes? I keep going away from the PC and the monitor goes off every 5 minutes. and then I come back after 15 minutes and stuff like that. what is the optimum setting?