Which consume more electricity a 12V x 50 watt halogen bulb or 240V x 50 watt halogen bulb?

Answer 1

Am I missing something??
We pay electricity by the current (I) we consume. So by you answer, we pay some 8 to 9 times more for the same power (W) with the 12 Volts bulb.
Am I right??

Answer 2

Watts is a unit of power or energy consumption.  50 watts is 50 watts regardless of voltage.  Watts equals volts x amps.  50 watts at 12v. uses 4.16 amps.  50 watts at 240v. uses .48 amps.  Same power.  There are transmission efficiency differences that will change consumption slightly but, basically, watts is watts.