In the United States of America the standard voltage is 120 V and the frequency is 60 Hz. You can use your electric appliances in the United States of America, if the standard voltage in your country is in between 110 - 127 V (as is in the US, Canada and most South American countries).
Also question is, are Singapore plugs the same as UK?
In Singapore the standard voltage is 230 V and the frequency is 50 Hz. You can use your electric appliances in Singapore, because the standard voltage (230 V) is the same as in the United Kingdom.
How much is Singapore voltage?
Voltage, Frequency and Plug/Outlet Type in Singapore. Electricity in Singapore is 230 Volts, alternating at 50 cycles per second. If you travel to Singapore with a device that does not accept 230 Volts at 50 Hertz, you will need a voltage converter.
Can you plug a 120v into a 240v outlet?
If you plug an 110V appliance in 220V outlet (same as 120v to 230v, 240v) you can only hope that some protection device disconnects the power to the appliance. If you plug a 220V device into 110V outlet, it will normally last a little longer before it dies.