Electric current is defined as
- A. the charge flowing per unit time past a point in the circuit
- B. the energy delivered per unit charge
- C. the resistance per unit length
- D. the potential difference per unit resistance only
Explanation
One ampere is one coulomb per second, so current measures rate of flow of charge. Energy per unit charge is potential difference, measured in volts, and confusing the two is the commonest error in this chapter. Conventional current is taken as the direction positive charge would move, which is opposite to the actual drift of electrons in a metal.
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