What does a light bulb marked 100 w mean? (a) uses 100 a of energy per second. (b) uses 100 j of current per second. (c) 100 c of charge flows through the bulb per second. (d) uses 100 v battery (e) none of these.

(E) none of these.

Explanation:

first that all we need the meaning of a Watt

" is a unit of power. In the International System of Units (SI) it is defined as a derived unit of 1 joule per second,[1] and is used to quantify the rate of energy transfer."  

definition taken from wikipedia.org

now with this concept we have that:

100 W means 100 J/s .Therefore it uses 100 J energy per second

therefore on the answers don't mention this three terms together

Joules, energy and second so the answer must be.

(E) None of these

iron would move it is magnetic there is a mag field around the current in the wire

in physics zero. in muscle fatigue could be high