
Corinne P. answered 08/07/13
Vandy PhD Candidate: Boosting math-esteem while reducing math-scorn!
"Ohm's law (named for nineteenth century German physicist George Simon Ohm, who derived it) is an equation describing the fundamental relationship between voltage, current, and resistance. It is usually stated as: E = IR, or V=IR, where E or V = voltage, in volts. E stands for "electromotive force" which is the same thing as voltage, and I = current, in amps, and R = resistance, in ohms."
Derived from the formula above: E=IR, they give you the formula E/R=I (where E=voltage, R=resistance, and I=current in amps).
Substitution: E/R = 100/5 = 20 amps
Choice D.
Reference: http://www.aikenamps.com/OhmsLaw.htm