An energy-saving light bulb has an efficiency of 45%. if 5w of light is emitted, what electrical power is required

If you're using the bulb as a source of light, then it's. 14/60 = 23.3% efficient.

If you're using it to heat a bird nest or a hamster cage, then it's. 46/60 = 76.7% efficient !

It just depends on your point of view, and what you consider 'useful' output.

as technology advances, new experiments often expose problems in accepted theories. c

hope i

-lavira: )

their crystal patterns have been disrupted by stress