100 Volts
Yes. As long as the voltage is designed for the lamp and the socket and fixture can handle the heat (from the rated power in watts), you can. You will probably find that the socket or connector for this lamp is different than the one intended.
See discussion page for more.
Household is 120/240 volts at 60Hz. The average wall socket is 120v 60Hz.
My first suspicion is you have a loose or disconnected neutral. TURN THE BREAKER OFF WHEN CHECKING THE CONNECTION. To include all points, even the obvious, make sure you have changed the lamps to known working lamps from another fixture. How do you know it has 120 volts at the socket? If you tested it with a voltage tester or a multimeter, which wires were you connected to? In order to troubleshoot you need to make three measurements, at the BOXif wall or ceiling mounted or RECEPTACLE if plugged in with a cord, not the fixture socket the lamp screws into. Hot to ground (volts AC) Should be 120 volts nominal. This can vary from about 110-130v. Hot to neutral (volts AC) Should be 120 volts nominal. Neutral to Ground (volts AC) Should be 0 volts. These wires are electrically joined at your main panel. If you have 120v hot to neutral, your circuit is working properly. Any problem will lie in the fixture or the connections to the fixture. If you do not have 120v to neutral but you do have 120v hot to ground, your neutral is not connected. TURN THE BREAKER OFF and check the connection. If you do not have 120v to neutral or120v to ground, your hot is not connected. TURN THE BREAKER OFF and check the connection. If you have anything other than 0 volts neutral to ground, your fixture connection may be okay, but your neutral is not connected properly going back to the main panel. This is a dangerous situation, and it can result in fire over time. In this case have an electrician inspect the situation immediately!
You don't, at least, not legally.
There should be no voltage on the neutral wire to ground. This is a serious situation. Call a qualified electrician to check this out.
It is 120V/60Hz
yes
120V appliance will not work on 220V. Use an instrument transformer or voltage regulator to adjust the high voltage to the desired level.
It is 120V
there is 120V across the circuit.
In America, a 2-pole breaker is controlling 240V. 120V per leg.