What will happen if i plug my 240 volts travel alarm clock into a 110 volts supply on a cruise ship ?

Answer
It will get damaged as a 110 volt supply (us type) has a frequency of 60 hz, european 220 volt has a frequency of 50hz - therefore there is a good chance that the clock will get damaged internally; as it may draw too much current due to the voltage difference and draw this current at the wrong frequency aswell. ..