What is the smallest number of polarities required for current flow? A. One – a negative terminal B. Two – a negative terminal and a positive terminal C. Three – negative, positive and neutral terminals D. Four – two negative and two positive E. None of the above

The correct answer is B. Two – a negative terminal and a positive terminal.

Current flow is the movement of electrons from a negative terminal to a positive terminal. Without a negative terminal,

Option A is incorrect because a single negative terminal is not enough to create a current flow. Option C is incorrect because a negative, positive, and neutral terminal are not necessary for current flow. Option D is incorrect because two negative terminals and two positive terminals would not create a current flow. Option E is incorrect because there is no other option that is correct.