Concept Flashcards

Concept Flashcards#

Lesson 3 — Introduction to Electrical and Computer Engineering#

What is current? The flow of electric charge (moving electrons) through a conductor.
What is voltage? The electric potential difference between two points – essentially the ‘pressure’ that can move electrons – measured in volts.
How is voltage measured? Always as a difference between two points (voltage is measured across a device).
What is ground? The 0V reference point in a circuit from which other voltages are measured (ground)
Does voltage exist without anything flowing? Yes. Voltage (electric potential) can exist even if no current is flowing.
How is current measured? By measuring the flow through a single point in the circuit (current is measured in-line at a specific point).
What is the mathematical formula for current? $$ I = \frac{\Delta q}{\Delta t} $$

where \(I\) is the charge flow per unit time (coulombs per second), which defines one ampere.

Which direction does current flow in this class? From the positive side to the negative side (conventional current flows + to –)
What is Ohm’s Law? Ohm’s Law: 𝑉 = 𝐼𝑅 (voltage equals current times resistance for a resistive element)
What is resistance? The opposition to the flow of electrons in a circuit (creating a voltage drop when current flows), measured in ohms (Ω)
What is the definition of power in electrical engineering? Power is the work done per unit time. In an electric circuit, 𝑃 = 𝐼𝑉 (current times voltage)
According to the textbook, how do total power input and output relate in a circuit? They are equal – the total power supplied by the sources equals the total power absorbed by the loads (power is conserved in the circuit).
Contents