Electric current

• What Is a Voltage Drop in a DC Circuit?
  Learn what voltage drop means in a DC circuit, how to calculate it with Ohm’s law, and how drops behave in series and parallel circuits.
• What Is the Electric Field Around a Current-Carrying Conductor?
  A steady current needs a longitudinal electric field inside a resistive wire; the field outside depends on surface charges, voltage, and the return-path geometry.