9.5 Current

• Science
• Middelbare school
• vwo
• Leerjaar 2

Lesson 5

 charge and current

Period 4 Electricity

Learning goals

• You can name the two types of charge and how they interact
  
• You can name the unit of charge.
  
• You're able to give a precies definition of electric current.
  
• You can name the unit of current.
  
• You're able to do calculations using electric current.
  

What is electric current?

Electric current is the flow of electrons through a complete circuit of conductors. It is used to power everything from our lights to our trains.

Electricity is a flow of charge 

Electricity is a flow of charge 

Conventionele current and electron flow

Electron current flows from the negative terminal to the positive terminal of the battery. The conventional current flows from the positive terminal of the battery to the negative terminal.

What is current 

Electrical current is a measure of the amount of electrical charge (electrons) transferred per unit of time. It represents the flow of electrons through a conductive material, such as a metal wire

Electric Charge

• The thing with electrons is: There are SO many!

• We don't measure charge in the number of electrons, but in batches.

• One such batch is one coulomb.

One coulomb

6 241 000 000 000 000 000 electrons

What is electricity (current)?

What is current?

You already know:

• Electricity is a flow of charge.

This can be

Quantified

First, pause the video and try to answer it for yourself. After that continue playing the video.

What is current?

You already know:

• Electricity is a flow of charge.

This can be

Quantified

The amount of coulomb flowing through an electric circuit per second — Coulomb/second

First, pause the video and try to answer it for yourself. After that continue playing the video.

What is current?

• Symbol: I
  
• Unit: Ampere (A)
• Formula:                           Current = Charge / time

Charge — Coulombs (C)

time — seconds (s)

I=​t​​Q​​

The amount of coulomb flowing through an electric circuit per second —  Coulomb/second

First, pause the video and try to answer it for yourself. After that continue playing the video.

Units of current

1. Ampere or amp (symbol: A) is the unit of electrical current.

2. A milliampere (often called "milliamp") is a unit of electric current . The symbol for milliampere is mA. 

1 milliampère = 0,001 A

A series circuit is defined as a circuit that contains only one path for current flow.

A circuit with a simple loop.

Series circuit 

One lamp off all lamps off

The current is the same in every part of the circuit 

Voltage in serie circuit 

The sum of the voltages across components in series is equal to the voltage of the supply. 

T