Yes. Computers are used in all sorts of equipment that need to operate without human intervention. Unless you include switching them on.
Domestic appliances like Washing machines, bread makers, TV's, DVD's, dish washers etc. all use digital computers in them. All work and follow complex instructions and take inputs from their own workings, without constant attention.
can a computer function/work without ac current
Not without surgical intervention while you're still in the womb.
To power your computer without a battery
No, a computer uses RAM (Random Axcess Memory) to function. RAM also determines the speed of you're computer; the more RAM the faster he computer.
Unlikely without extraordinary medical intervention, but remotely possible.
The hard drive
Computer aided, means that solution are found using a compter and then analysed and used by human intervention. Compter integrated, means that the solutions are applied directly to the machines in the manufacturing process, without human intervention.
You cannot get free Gems on Clash of Clans without a computer.
There are no disadvantages of computer hardware, because without it, the computer would not be able to function, or even exist for that matter!
No, but it won't function without one.
Yes, this is an internal function of the computer. You need a writable cd and the file on your computer.
Yes, it is. Because it is outside the computer, is a secondary device because your computer can function without it.