Choose your answer: Is "A lamp with the same rated lifetime but designed for 230 V would produce only around 12.8 lumens per watt, and a similar lamp designed for 30 volts (train lighting) would produce as much as 19.8 lumens per watt." a good answer to the question "How does filament size relate to voltage level?"
Options:
a). yes.
b). no.
b).