# Electrical Circuits

An electrical circuit is a closed-loop path through which current can flow

An electrical circuit can be made up of most any materials but practically speaking, circuits are typically comprised of electrical devices

Wires

Batteries

Resistors

Switches

Conventional current flows from high potential to low potential

# Voltmeters

Voltmeters measure the potential difference between two points in a circuit

Voltmeters are connected in parallel with the element to be measured

If a voltmeter is connected correctly, you can remove it from the circuit without breaking the circuit

Voltmeters have very high resistance

# Ammeters

Ammeters measure the current flowing through an element of a circuit

Ammeters are connected in series with the circuit, so that the current to be measured flows through the ammeter

The circuit must be broken to correctly insert an ammeter

Ammeters have very low resistance to minimize the potential drop through the ammeter

# Series Circuits

Series circuits have only a single current path

Removal of any circuit element causes an open circuit

# Kirchhoff's Laws

Kirchhoff's Laws are tools utilized in analyzing circuits

Kirchhoff's Current Law (KCL) states that the sum of all current entering any point in a circuit equals the sum of all current leaving any point in a circuit

Restatement of conservation of charge

aka "Junction Rule"

Kirchhoff's Voltage Law (KVL) states that the sum of all the potential drops in any closed loop of a circuit has to equal zero

Restatement of conservation of energy

aka "Loop Rule"