Yes. In North America household power is 120/240V at 60Hz and 45 Watts means it will only draw 0.375 Amperes. So it can safely be used
It depends on the appliance. All appliances are required to have a 'nameplate' which contains information on their power and voltage ratings.
Its resistance.
what is the power rating of energy
Power consumed by an electrical appliance will increase with a reduction of applied voltage.
Power consumed by the appliance = (DC supply voltage) x (DC current)
only the appliance power
If it is plugged in yes.
A cord to conduct power to an electrical appliance.
what is the power rating of energy
Yes, either way, the power is cut to that appliance.
1440 Watts
It means that, to operate at its rated power, the appliance must be provided with a 230-V supply.