Lesson 10

• Nask
• Middelbare school
• havo, vwo
• Leerjaar 2

Electricity — Ohm's Law

This lesson

• Current - Voltage - Resistance — Recap
  
• Ohm's law

Learning goals

• You can explain what current, resistance and voltage are in your own words and name the correct unit for each.

• You can describe the difference between how current is measured and how voltage is measured.

• You can describe how voltage gets divided over series and parallel circuits.

• You can name Ohm's law in words and in symbols and you can do calculations with it.

Current – Resistance – Voltage

Link

Current

Symbol: I

Unit: Ampere

 Symbol for Ampere: A

The amount of charge (measured in Coulombs)

flowing through a circuit per second (Coulombs / second )

Examples:

• Current = 0.8 Ampere
  
• I = 0.8 A
  

Resistance

Symbol: R

Unit: Ohm

 Symbol for Ohm: Ω

Resistance is the opposition to current flow.

Examples:

• Resistance = 5 Ohm
  
• R = 5 Ω
  

Voltage

Symbol: V

Unit: Volt

 Symbol for Volt: V 

Voltage (potential difference) is the difference in the amount of electrical energy between two points in a circuit.

Examples:

• Voltage = 5 volts
  
• V = 5 V
  

Ohm's law

Ohm's law

Current=​Resistane​​Voltage​​

I=​R​​V​​

Ohm's law

Current=​Resistane​​Voltage​​

I=​R​​V​​

• Current (I)  —       Ampere (A)
  
• Voltage (V) —       Volt (V)
  
• Resistance (R) — Ohm (Ω)
  

Link

Practice exercise

A) An average refrigerator works on a voltage of 120 Volts. A normal resistance for a refrigerator can be 45 Ohm. Calculate the current flowing through a refrigerator that has these properties.

B) What would the resistance on a fridge that has the same voltage have to be if it has a current of 2.4 Ampere flowing through it?

Learning goals

• You can explain what current, resistance and voltage are in your own words and name the correct unit for each.

• You can describe the difference between how current is measured and how voltage is measured.

• You can describe how voltage gets divided over series and parallel circuits.

• You can name Ohm's law in words and in symbols and you can do calculations with it.