Nowadays, you can buy DC to DC convertors that do the conversion in a single module.
A cheaper solution, however, would be to use a chain of diodes - each diode will drop 0.7 volts so 4 diodes will drop 2.8 volts, reducing 12 volts to 9.2 volts.
No
You give it more volts and it will burn out something!!
No. You need 12 volt AC to run a 12 volt AC motor, not 12 volt DC.
Depends on the led forward bias threashold, if its a typical led it will be .7 volts so, .7x6=4.2V, so pick a resistor that will drop around 7 volts. What is the current? Then just to V=IR, 7=IR.
This seems like a question from an electrical course, and is probably best answered by your course materials. It's your test question, not ours, and there won't always be someone to ask the answer of. Earn your diploma.
No.
You need an ac-dc converter to reduce your house voltage to 12 volts
12 volts DC
12 volts DC.
12 volts DC
12 volts DC.
12 volts DC.
dc - the voltage is a constant 12 volts nominally in a normal car battery.
12 volts DC.
12 volts DC.
You will have 24 volts DC.
12.6 volts as read with a digital DC volt meter.