Topic study hub
Current, potential difference and resistance
This topic connects the microscopic idea of charge flow to practical circuit diagrams, Ohm's law, component characteristics and measurement techniques.
49
Objectives
245
Flashcards
245
Questions
90 min
Study time
AQAGCSEPhysicsElectricity
Choose a revision tool
Start revising Current, potential difference and resistance
Syllabus checklist
What you need to know
49 objective pages available
Standard circuit diagram symbols6 objectives
- Recognise and use standard circuit symbols for common electrical components.
- Draw circuit diagrams using the correct symbols for cells, batteries, switches, lamps, resistors and variable resistors.
- Draw circuit diagrams using the correct symbols for fuses, ammeters, voltmeters, diodes, LEDs, thermistors and LDRs.
- Interpret circuit diagrams to identify how components are connected.
- Use circuit diagrams to plan and check simple measurement circuits.
- Apply WS 1.2 by representing circuits accurately with standard scientific symbols.
Electrical charge and current10 objectives
- Explain that charge flows in a closed circuit only when the circuit includes a source of potential difference.
- Define electric current as the flow of electrical charge.
- Describe current as the rate of flow of electrical charge.
- Recall and apply the equation Q = I x t.
- Identify charge flow Q in coulombs, current I in amperes and time t in seconds.
- Calculate charge flow when current and time are known.
- Calculate current when charge flow and time are known.
- Calculate time when charge flow and current are known.
- State that current has the same value at any point in a single closed loop.
- Use MS 3b and MS 3c skills when rearranging and calculating with Q = I x t.
Current, resistance and potential difference14 objectives
- Explain that current through a component depends on resistance and potential difference.
- Explain that a larger resistance gives a smaller current for the same potential difference.
- Use the term potential difference accurately and recognise voltage as an accepted alternative term.
- Recall and apply the equation V = I x R.
- Identify potential difference V in volts, current I in amperes and resistance R in ohms.
- Calculate potential difference when current and resistance are known.
- Calculate current when potential difference and resistance are known.
- Calculate resistance when potential difference and current are known.
- Rearrange V = I x R to solve circuit problems.
- Required practical activity 3: use circuit diagrams to set up and check circuits that investigate factors affecting resistance.
- Required practical activity 3: investigate how wire length affects resistance at constant temperature.
- Required practical activity 3: investigate combinations of resistors in series and parallel.
- Apply AT 1, AT 6 and AT 7 skills when using circuit apparatus and meters.
- Use MS 3b and MS 3c skills when calculating current, potential difference and resistance.
Resistors19 objectives
- Explain that some resistors have constant resistance while others change resistance as current changes.
- Describe an ohmic conductor at constant temperature as having current directly proportional to potential difference.
- Explain that an ohmic conductor has constant resistance as current changes when temperature is constant.
- Describe how the resistance of a filament lamp increases as filament temperature increases.
- Describe how current through a diode flows in one direction only.
- Explain that a diode has very high resistance in the reverse direction.
- Describe how the resistance of a thermistor decreases as temperature increases.
- Explain how thermistors can be used in circuits such as thermostats.
- Describe how the resistance of an LDR decreases as light intensity increases.
- Explain how LDRs can be used in circuits such as automatic lighting.
- Explain how to measure the resistance of a component by measuring current through it and potential difference across it.
- Draw an appropriate resistance-measurement circuit using correct symbols.
- Investigate the relationship between thermistor resistance and temperature.
- Investigate the relationship between LDR resistance and light intensity.
- Use I-V graphs to decide whether circuit elements are linear or non-linear.
- Relate I-V graph shapes to the function and properties of resistors, filament lamps and diodes.
- Required practical activity 4: construct circuits to investigate I-V characteristics for a filament lamp, a diode and a resistor at constant temperature.
- Apply AT 6 and AT 7 skills when constructing and using I-V characteristic circuits.
- Apply MS 4c, MS 4d and MS 4e skills when interpreting circuit graphs.
Key terms
circuit symbolstandard circuit symbolscircuit diagramcircuit diagrams correctcircuit diagrams componentscircuit diagrams planapplyrepresenting circuits accuratelycharge flowcharge flows closedcurrentelectric current flow
Exam tips
- Standard circuit diagram symbols exam tip 1: Use precise subject-specific vocabulary when you explain how to recognise and use standard circuit symbols for common electrical components..
- Standard circuit diagram symbols exam tip 1: Use precise subject-specific vocabulary when you explain how to draw circuit diagrams using the correct symbols for cells, batteries, switches, lamps, resistors and variable resistors..
Common mistakes
- Standard circuit diagram symbols common mistake 1: Answer by clearly explaining how to recognise and use standard circuit symbols for common electrical components..
- Standard circuit diagram symbols common mistake 1: Answer by clearly explaining how to draw circuit diagrams using the correct symbols for cells, batteries, switches, lamps, resistors and variable resistors..
Practice preview
- Which option best matches the approved learning objective for Standard circuit diagram symbols (1)?
- A student is answering an AQA Electricity question about Standard circuit diagram symbols. Which choice best applies standard circuit symbols?
- In Current, potential difference and resistance, which revision statement keeps standard circuit symbols tied to the approved learning objective?
Continue by objective
Objectives are grouped by subtopic so students can jump straight to the exact skill they want to revise.
Related topics