Intro to Electricity

Intro to Electricity

When Mr. C becomes Zordon from Migthy Morphin Power Rangers

Electricity is a form of energy that results from the flow of charged particles including protons and electrons.

Electrical energy can be transformed into many forms that are useful to us, such as light, heat, sound, and motion.

Electrical energy is has the ability to to be converted, stored, transmitted, and reconverted efficiently into other forms of energy.

• Electrical energy has three properties: voltage, resistance, and current,

• Understanding the relationship between current, voltage, and resistance allows engineers to design efficient, safe, and functional electrical circuits.

Electrical circuits are made up of:

• an energy source to provide voltage,

• conductors to allow current travel,

• insulators to limit current travel,

• and a load.

Electrical circuits provide an uninterrupted path for current travel in two distinct categories of design: 

• series circuits 

• and parallel circuits.

Open Ended

Electricity is a component in many products and design systems, so an engineer needs a foundation of knowledge about electricity.

List one or more careers you can think of, that may require someone to have a good understanding of electrical energy to in order to perform their job requirements correctly

Feel free to think outside the box!

How Does Electricity Work?

• A water system can provide an analogy to understand an electrical system.

How Does Electricity Work?

A water system can provide an analogy to understand an electrical system.

Electrical Circuit Components

All electrical circuits have these basic components: source, conductor, load (resistance), and sometimes, a switch. The electrons must have a continuous path from the source through the circuit back to the source. Otherwise, it’s like water flowing through a pipe that is stopped at a blockage. The circuit cannot be completed, so the flow stops.

Kirchoff's Voltage Law

• The sum of all voltage drops in a series circuit equals the total applied voltage.

• Voltage drop is defined as the amount of voltage loss that occurs through all or part of a circuit due to resistance.

•  $V_{T_{ }}=V_1+V_2+....+V_n$  

Kirchoff's Voltage Law

• The sum of all voltage drops in a series circuit equals the total applied voltage.

• Voltage drop is defined as the amount of voltage loss that occurs through all or part of a circuit due to resistance.

•  $V_T\ =\ V_1+V_2+....+V_n$  

Kirchoff's Current Law

• The total current in a parallel circuit equals the sum of the individual branch currents

•  $I_T\ =\ I_1+I_2+....+I_n$  

Components in a circuit can be connected in one of two ways, in a series circuit or parallel circuit.`

For the series circuit shown, use the laws of circuit theory to calculate the following:

• The total resistance (R_T)

• The current flowing through each component (I_T, I₁, I₂, and I₃)

• The voltage across each component (V_T, V₁, V₂, and V₃)

• Use the results to verify Kirchhoff’s Voltage Law

For the PARALLEL circuit shown, use the laws of circuit theory to calculate the following:

• The total resistance (R_T)

• The current flowing through each component (I_T, I₁, I₂, and I₃)

• The voltage across each component (V_T, V₁, V₂, and V₃)

• Use the results to verify Kirchhoff’s Current Law

Measuring Values of an Electrical Circuit

Properties of an electrical circuit, such as voltage, current, and resistance, can be measured using a multimeter. This video shows how these values are measured and how to correctly measure a specific value using the multimeter. There is no associated audio.

Multiple Choice

Calculate the current flowing in the circuit shown

• 35 mA

• 36 mA

• 0.6 A

• 1.6 A

Multiple Choice

What value will a multimeter show when set on a resistance measurement setting, and the probes are touching the circuit as shown?

• infinite

• 620 Ω

• 0 Ω

• 9 Ω

Multiple Choice

What value will a multimeter show when set on a voltage measurement setting and the probes are touching the circuit as shown?

• 9V

• 0 V

• 620 V

Multiple Choice

Calculate the voltage applied to the circuit shown

• 24 V

• 23 V

• 1 V

Fill in the Blanks

A circuit contains a 6 V battery and three resistors connected in parallel with each other and with the battery.

R₁ = 2 Ω

R₂ = 3 Ω

R₃ = 6 Ω

What is the current across Resistor R₁ ?

Fill in the Blanks

A circuit contains a 6 V battery and three resistors connected in parallel with each other and with the battery.

R₁ = 2 Ω

R₂ = 3 Ω

R₃ = 6 Ω

What is the current across Resistor R ₂?

Fill in the Blanks

A circuit contains a 6 V battery and three resistors connected in parallel with each other and with the battery.

R₁ = 2 Ω

R₂ = 3 Ω

R₃ = 6 Ω

What is the current across Resistor R ₃?

Fill in the Blanks

A circuit contains a 6 V battery and three resistors connected in parallel with each other and with the battery.

R₁ = 2 Ω

R₂ = 3 Ω

R₃ = 6 Ω

What is the current running through the battery?