Can I use 5V instead of 12V?

Can I use a 5V adapter to a 12V object and work

Most likely not. But as always it depends on what product you are trying to power up with the 5V instead of a 12V source. A fan may work but slow, a heater will work but at 17% power output, a peltier cooler/heater will work but will not remove as much heat.

What happens if I use a 5V adapter on a 12V device

That said, I'd suggest against using a 5 volt supply for a 12 volt device. For a start, if it really requires 2 volts (or close to it), you will have a problem because 12 x 2 = 24 watts, while 5 x 2 = 10 watts, so the power supply is under-specced to do the job at maximum load.

Is 5V to 12V converter safe

Yes, DC/DC step-up (boost) converters are safe. You'll need to look at current, efficiency and noise.

Can I use 5V charger to charge 12V battery

No way it'll do 12V or any other chemistry. To charge any battery, you need to give it a voltage higher than what it's going to charge to.

Can a 5V motor run on 12V

You can not power a 5V motor with a 12V supply, unless you keep it submerged in liquid nitrogen to deal with the heat.

Can I use 5V charger instead of 12V

No, the charger needs to have an output a little higher than the battery you are trying to charge. If you use less, no charging will occur. Can I charge a 12V battery with a 5V charger Presuming that you are talking about a charger as an integrated product purchased off-the-shelf, you cannot.

Can you power a 12V device with 5V

The device will very likely burn out. In addition, depending on what the device is and the capacity of the 12V supply, connecting a 12V supply to a device rated 5V max could lead to a hazard – fire, explosion, etc.

Can I use a 5V power supply on a 12V device

That said, I'd suggest against using a 5 volt supply for a 12 volt device. For a start, if it really requires 2 volts (or close to it), you will have a problem because 12 x 2 = 24 watts, while 5 x 2 = 10 watts, so the power supply is under-specced to do the job at maximum load.

Is 5V stronger than 12V

So the 5V system is 2.4 times more efficient than the 12V system, meaning you need to provide 2.4 times as much power as a 5V system to achieve the same outcome. Where is all this extra power used up in the 12V system you may ask Well, it is dissipated in the form of heat!

Can I use a 5V LED on 12V

A 5V LED must not be run on 12V. But there are lots of options to convert 12V to 5V. As Jason Vaughan notes, a USB charger intended for a car will do a good job – unless you need a lot of power.

What happens if I plug a 12V into a 5V

You cannot use a 12V power supply on a 5V. It will cause the device to draw more current than it is designed for and will likely burn out, causing fire hazards and explosions. In other words, if the applied voltage is more than the maximum rated voltage then the device will undoubtedly fail due to overvoltage.

Can you charge 12V with 5V charger

No way it'll do 12V or any other chemistry. To charge any battery, you need to give it a voltage higher than what it's going to charge to.

Can I use A 5V power supply on A 12V device

That said, I'd suggest against using a 5 volt supply for a 12 volt device. For a start, if it really requires 2 volts (or close to it), you will have a problem because 12 x 2 = 24 watts, while 5 x 2 = 10 watts, so the power supply is under-specced to do the job at maximum load.

Can I plug 12V into 5V RGB

Without question the 2 versions of RGB are not interchangeable and do not work together. Plugging 5v circuit into 12v header may cause damage to the product you are plugging in. Notice a couple things.