Current is reported as the number of charges per unit time passing through a boundary. Visualize placing a boundary all the way through a wire. Station yourself near the boundary and count …

We look at the inductor i-v equations and notice how important it is to give inductor current a place to flow. Written by Willy McAllister. The inductor is one of the ideal circuit elements. Let's put …

Review the key terms, equations, and skills related to current, resistance, and resistivity, including how to find the current direction and what resistance depends on.

Demonstrates the capacitor i-v equation by deriving the voltage on a capacitor driven by a current source. Written by Willy McAllister.

Learn Drift velocity (concept & intuition) Drift velocity - formula & derivation Current from drift velocity (I = neAvd) Ohm's law - derivation (using drift velocity)

Let's practice some problems to better understand the concept of electric power and its relation with voltage and current in a circuit.

When electric current flows through a high-resistance material like the filament in a light bulb, it encounters resistance, causing energy to convert into heat due to collisions between electrons …

A brief guide to the reference information—AKA the formula sheet—available to test takers on the SAT Math section.

Displacement current isn't always equal to conduction current. In a capacitor, they match up, but in a steady DC circuit, there's only conduction current. Simple as that!

What is the current at the end of this pulse here? So, at two milliseconds, let's figure out what the current is, and that equals, at two milliseconds it's two times two milliseconds divided by 10 …