The old style (incandescent) light bulb converts more energy
into heat than it does into light. If you're using it mainly as a
source of light, then it's a bummer, and its efficiency is very low.
BUT ... if you're using an incandescent light bulb as a heater, then
its efficiency is much better. It all depends on your point of view.
I think it is D
Hope my answer help you?
Answer:
Bottle opener works on a fulcrum.
Explanation:
A bottle opener is a second-class lever because the pivot point is at one end of the opener and the load is in the middle.
