That's called the wave's "wavelength" .
It's called the periodic table because it arranges the elements the into repeating sets known as periods. this is defined by the <span>covalence of an element and the number of electrons i has in its outermost shell. I feel the the Best answer would be B. sorry if im wrong but i hope i helped :)</span>
Explanation:
current = velocity/resistance
I = V/R
15/4
current = 3.75A
hope this helps...