yes, but it may burn out
A 50 watt bulb designed to run on 12 volts takes 4.17 amps. A 50 watt bulb designed to run on 230 volts takes 0.217 amps.
No, you will need two 12 volt batteries connected in series to give the 24 volts necessary to run the pump. It will not run on 12 volts.
If the bulb is a 40 watt, 120v bulb, you would need 20 6 volt batteries wired in series, or 80 (!) 1.5 volt batteries. 1.5 volt batteries are AAA, AA, C, D, etc. Since this solution is rather extravagant, try finding a light bulb made for an RV. These typically run off of 12 volts, and you can get a single 12 volt battery, or 2 6 volt batteries, to run this bulb.
No. You need 12 volt AC to run a 12 volt AC motor, not 12 volt DC.
12 volts is enough for a 12-volt 100-watt light bulb. It would not be enough for a 120-volt or 240-volt bulb.
A couple quick questions first please ... why are you using a 12 volt lamp in a 6 volt system? Have you increased the system voltage? Simply replacing a 6 volt bulb with a 12 volt bulb will cause the 12 volt bulb to burn dim ... Some systems have electrical circuits that drop (decrease) the voltage to certain units (like lights). For instance, your car is a 12 volt system (actually 14 when alternator is operating) and that 12 volts can be reduced with resistors to supply only 6 of those volts to a light ... or other device. Simply replacing with a 12 volt lamp will cause it to burn dimmer. Sorry to answer with a question but, I am just curious ...
If it is a 12 volt panel it will light a 12 volt bulb. Most likely it is not a 12 volt panel, it is some other voltage, so you then need equipment like an inverter to convert the energy to 12-volt energy.
You don't.
The bulb with the lowest resistance. Current = Volts / Resistance
Yes. Since the coil is run at full voltage when starting 12 volts may be too much for a 6 volt ignition coil. It would be at about 8 volts when running. There is a starting resistor.
The potential difference has to be 12 Volts since the light bulb will use 12 Volts (or Joules per Coulomb!) of energy. Voltage has to be 0 when it reaches the negative electrode of the battery, so you know that the 12 Volts have to have been consumed by the bulb!
No. The bulb will burn out.