A device which requires 1000mA at 9 volts in order to operate will not work from an output of 500mA. This output is only half the power requirement of the device.
No! it wont. Or at least for a VERY short time. You will destroy the device.
No. Usually it's a -/+ 10% difference. So, a 9v would need at least 7.2 volts or more
No, because the provided rating of 12volt, 2.7Amp equivalent to 2700 mA (milli amphere) is a much higher as to the adapter said 12volt, 1000 mA (Milli Amphere).
Your power adapter is rated up to 30 volts at 1000ma. (1 amp.) If you have a device which only draws 1 milliamp, then it should work with this adapter, as long as the voltage is correct.
A display ADAPTER is neither. The Display is an output device.
No you can not. The power supply output of 5 volts is under sized. There is no way that a 45 volt device would operate from it. You will need to find a power supply of 45 volts.
Your question is confusing, but if you are asking whether you can use a 9V/250 mA adapter to supply a load device rated at 5 V/1000 mA, then the rule is quite straightforward. The adapter's rated output voltage must match that of the intended load, but its rated current must exceed that of the load. So in your example, you cannot use the adapter with the intended load.
No, if your device require 3.0A, 1500ma adapter which is 1.5A is not enough, voltage wise is fine, your adapter adapter will get warm, then overheat, then very likely fail.
Yes - it will just take a little longer to charge the device.
12v 1000mA means that the maximum output of that unit is 1000 milliamps at 12 volts. 12v 150 mA means that the maximum output of that unit is 150 milliamps at 12 volts. So if you need 150 milliamps at 12v either will do. BUT if you need over 150 milliamps at 12v then you must go for the 1000 mA unit. By the way there are 1000 milliamps in 1 amp.
No. The device requires a 9V supply capable of delivering at least 1A. You're trying to supply it with a 5V supply. Go buy the right adapter. Just because there's a physical fit, it doesn't mean the part is the correct one. If the 9V supply can supply a little more than 1A (say, 1100 / 1200 mA) then that would be acceptable. If can only supply 900 mA, it may not work correctly.
Assuming the plug fits, and that the polarity is correct it'll work fine. Drawing less amps than the source can deliver isn't a problem, it'd be a bit like filling a glass from a pitcher. Drawing more amps than the source can deliver is what you need to watch out for, that can cause overheating and all sorts of nasty failures.
No, the adapter's power output has to be equal to or greater that the current draw of the device.