Voltage and Currents

power

the rate at which energy is used.

voltage

the potential energy per charge

electrical potential energy

energy due to electric charges

circuit

• a closed loop that allows electric current to flow.

• typically consists of a power source (like a battery), conductive paths (wires), and components (such as resistors, capacitors, or switches) that control the flow of electricity.

• can be classified as series or parallel, depending on how components are arranged.

electric charge

a property of matter that assigns a value based on the number of electrons

resistor

an electronic device that resists electric current

resistance

the amount that a material opposes the flow of charge

current

the rate that charges move by a given point

unit of resistance

Ohms (Ω)

unit of current

Amperes (A)

unit of voltage

Volts (V)

unit of electric potential energy

Joule (J)

unit of power

Watt (W)

unit of charge

Coulomb (C)

symbol of current

I

symbol of voltage

V

symbol of electric potential energy

∆PE

symbol of resistance

R

symbol of charge

q

symbol of power

P

ammeter

A device used to measure the electric current flowing through a circuit. It is typically connected in series with the circuit to ensure accurate readings of current in amperes.

voltmeter

an instrument used for measuring electric potential difference between two points in an electric circuit. It is connected in parallel. It usually has a high resistance so that it takes negligible current from the circuit.

schematic diagram

a graphical representation of a plan or a model that is presented in a simple, accessible way

conductor

an object or type of material that allows the flow of charge in one or more directions. common in materials made of metal

insulator

a material in which electric current does not flow freely. The atoms of them have tightly bound electrons which cannot readily move.

parallel circuit

a circuit that has two or more paths for the electricity to flow, the loads are || to each other.

series circuit

a circuit that has only one path through which its current can flow. thus, all of the components in a series connection carry the same current

electrical load

any electrical device or component that consumes electrical energy and converts that energy into another form