Ohm's Law: voltage, current, resistance

PROCEDURAL

Science›Energy|Ages 12—13|ID: mt_H3ZDK0EYNV

Apply Ohm's Law (V = IR) to calculate current, voltage, or resistance in a simple circuit, and explain that resistance opposes the flow of current

Mastery Evidence

States Ohm's Law as V = IR and identifies the units for each quantity
Rearranges V = IR to find the unknown value given the other two
Explains that resistance opposes current flow and identifies factors that affect resistance (material, length, thickness)

Assessment Prompt

“If [child] doubles the resistance in a circuit while keeping the battery the same, can they predict what happens to the current and explain using the V = IR formula?”

Curriculum Standards1 alignment

MS-PS2-3Next Generation Science Standards (NGSS) Middle Schoolcodes only

Standard code — full text not included in this dataset.

Prerequisites1

Current, voltage, and what they measure
hardAges 11—12

Show full prerequisite tree

Current, voltage, and what they measure hard
Ohm's Law relates voltage (V), current (I) and resistance (R) — requires prior understanding of what each quantity means
- Circuit vocabulary hard
  Understanding current as charge flow and voltage as energy per charge requires these exact technical terms
- Drawing circuits with proper symbols hard
  Understanding current and voltage as quantities requires the ability to read circuit diagrams with standard symbols, established at KS2
  - Why circuit components behave differently soft
    Understanding component variations supports interpreting and drawing circuit diagrams
    - Circuit vocabulary hard
      Comparing circuit component function requires component vocabulary: bulb, buzzer, switch, resistance
    - More batteries, brighter bulb hard
      Must understand voltage-brightness relationship before comparing component variations
      - How switches work hard
        Must understand switches and circuits before investigating voltage effects
        
        Will the bulb light up? hard
        Must understand complete loops before understanding how switches open/close them
        
        Building a simple circuit hard
        Must build circuits before predicting whether a lamp will light
        
        What uses electricity at home hard
        Must identify electrical appliances before building circuits
      - Circuit vocabulary hard
        Associating brightness with voltage requires 'voltage', 'current', and 'series circuit' vocabulary
      - How energy travels around soft
        Energy transfer concept supports understanding voltage as energy per charge
        
        Light & Seeing in the Dark soft
        Light knowledge supports understanding energy transfer by light
        
        Light & Sound Vocabulary hard
        Observing that objects need illumination to be seen requires the 'light source' vocabulary
        
        Naming types of energy hard
        Describing energy transfer by sound, light, heat, and electric current requires energy type vocabulary
        
        Building a simple circuit hard
        Must know circuits before understanding energy transfer by electric current
        
        What uses electricity at home hard
        Must identify electrical appliances before building circuits
        
        Vibrations & Sound soft
        Sound knowledge supports understanding energy transfer by sound
        
        Light & Sound Vocabulary hard
        Understanding vibrating materials and sound requires 'vibration' vocabulary
        
        Communication with Light & Sound hard
        Must understand how sound works before designing a communication device using it
        
        Light & Seeing in the Dark hard
        Must understand how light works before designing a communication device using it
        
        Light & Sound Vocabulary hard
        Observing that objects need illumination to be seen requires the 'light source' vocabulary
  - More batteries, brighter bulb hard
    Must understand circuit behaviour before representing circuits with formal symbols
    - How switches work hard
      Must understand switches and circuits before investigating voltage effects
      - Will the bulb light up? hard
        Must understand complete loops before understanding how switches open/close them
        
        Building a simple circuit hard
        Must build circuits before predicting whether a lamp will light
        
        What uses electricity at home hard
        Must identify electrical appliances before building circuits
    - Circuit vocabulary hard
      Associating brightness with voltage requires 'voltage', 'current', and 'series circuit' vocabulary
    - How energy travels around soft
      Energy transfer concept supports understanding voltage as energy per charge
      - Light & Seeing in the Dark soft
        Light knowledge supports understanding energy transfer by light
        
        Light & Sound Vocabulary hard
        Observing that objects need illumination to be seen requires the 'light source' vocabulary
      - Naming types of energy hard
        Describing energy transfer by sound, light, heat, and electric current requires energy type vocabulary
      - Building a simple circuit hard
        Must know circuits before understanding energy transfer by electric current
        
        What uses electricity at home hard
        Must identify electrical appliances before building circuits
      - Vibrations & Sound soft
        Sound knowledge supports understanding energy transfer by sound
        
        Light & Sound Vocabulary hard
        Understanding vibrating materials and sound requires 'vibration' vocabulary
        
        Communication with Light & Sound hard
        Must understand how sound works before designing a communication device using it
        
        Light & Seeing in the Dark hard
        Must understand how light works before designing a communication device using it
        
        Light & Sound Vocabulary hard
        Observing that objects need illumination to be seen requires the 'light source' vocabulary
- More batteries, brighter bulb hard
  KS2 observation that more cells gives brighter bulbs is the empirical foundation for defining voltage as energy per charge
  - How switches work hard
    Must understand switches and circuits before investigating voltage effects
    - Will the bulb light up? hard
      Must understand complete loops before understanding how switches open/close them
      - Building a simple circuit hard
        Must build circuits before predicting whether a lamp will light
        
        What uses electricity at home hard
        Must identify electrical appliances before building circuits
  - Circuit vocabulary hard
    Associating brightness with voltage requires 'voltage', 'current', and 'series circuit' vocabulary
  - How energy travels around soft
    Energy transfer concept supports understanding voltage as energy per charge
    - Light & Seeing in the Dark soft
      Light knowledge supports understanding energy transfer by light
      - Light & Sound Vocabulary hard
        Observing that objects need illumination to be seen requires the 'light source' vocabulary
    - Naming types of energy hard
      Describing energy transfer by sound, light, heat, and electric current requires energy type vocabulary
    - Building a simple circuit hard
      Must know circuits before understanding energy transfer by electric current
      - What uses electricity at home hard
        Must identify electrical appliances before building circuits
    - Vibrations & Sound soft
      Sound knowledge supports understanding energy transfer by sound
      - Light & Sound Vocabulary hard
        Understanding vibrating materials and sound requires 'vibration' vocabulary
      - Communication with Light & Sound hard
        Must understand how sound works before designing a communication device using it
        
        Light & Seeing in the Dark hard
        Must understand how light works before designing a communication device using it
        
        Light & Sound Vocabulary hard
        Observing that objects need illumination to be seen requires the 'light source' vocabulary

Unlocks1

Series vs parallel circuits
hardAges 12—13