GCSE Physics Revision — Ohm's Law
Revise Ohm's Law for GCSE Physics. Step-by-step explanation, worked examples, common mistakes and exam-style practice aligned to AQA, Edexcel, OCR, WJEC, Eduqas, CCEA, Cambridge International (CIE), Pearson Edexcel International, OxfordAQA International, SQA, IB, AP.
At a glance
- What StudyVector is
- An exam-practice platform with board-aligned questions, explanations, and adaptive next steps.
- This topic
- Ohm's Law in GCSE Physics: explanation, examples, and practice links on this page.
- Who it’s for
- Students revising GCSE Physics for UK exams.
- Exam boards
- Practice is aligned to major specifications (AQA, Edexcel, OCR, WJEC, Eduqas, CCEA, Cambridge International (CIE), Pearson Edexcel International, OxfordAQA International, SQA, IB, AP).
- Free plan
- Sign up free to use tutor paths and feedback on your answers. Free access is 7 days uncapped, then 45 min revision/day. Pricing
- What makes it different
- Syllabus-shaped practice and progress tracking—not generic AI answers.
Topic has curated content entry with explanation, mistakes, and worked example. [auto-gate:promote; score=70.6]
Next in this topic area
Next step: IV Characteristics
Continue in the same course — structured practice and explanations on StudyVector.
Go to IV CharacteristicsTopic explanation
What is Ohm's Law?
Ohm's Law states that the current through a conductor is directly proportional to the potential difference across it, provided the temperature and other physical conditions remain unchanged. This relationship is expressed by the equation V = IR, where V is voltage, I is current, and R is resistance.
Board notes: A key law in all GCSE Physics specifications (AQA, Edexcel, OCR). Understanding which components are ohmic and non-ohmic is crucial.
Step-by-step explanationWorked examples
Worked example 1: Core method
A resistor has a resistance of 12Ω and the potential difference across it is 6V. What is the current flowing through it? Solution: Using Ohm's Law, I = V/R. I = 6V / 12Ω = 0.5A.
Worked example 2: Exam variation
Now change one detail in the question and keep the same structure: name the Ohm's Law idea being tested, show the method or evidence, then explain why it answers the command word. This helps GCSE Physics students avoid memorising one surface pattern.
Worked example 3: Mark-scheme check
Finish by checking the answer against marks: one point for the correct Ohm's Law idea, one for accurate working or evidence, and one for a precise final statement. If any step is vague, rewrite it before moving to timed practice.
Mini lesson for Ohm's Law
1. Understand the core idea
Ohm's Law states that the current through a conductor is directly proportional to the potential difference across it, provided the temperature and other physical conditions remain unchanged. This relationship is expressed by the equation V = IR, where V is voltage, I is current, and R is resistance.
Can you explain Ohm's Law without copying the notes?
2. Turn it into marks
A resistor has a resistance of 12Ω and the potential difference across it is 6V. What is the current flowing through it?
Underline the method, evidence, or command-word move that would earn credit in GCSE Electricity.
3. Fix the likely mark leak
Watch for this mistake: Applying Ohm's Law to non-ohmic conductors. Ohm's Law only applies to components with a constant resistance, like a resistor at a constant temperature. It does not apply to filament lamps or diodes.
Write one correction rule before doing another practice question.
Practise this topic
Start with low-focus cards for Ohm's Law, then move into full exam-style practice when you want the heavier session.
Mini quiz: Ohm's Law
Three quick checks for revision practice. They are original StudyVector prompts, not official exam-board questions.
Question 1
In one GCSE sentence, explain what Ohm's Law is testing.
Answer: Ohm's Law states that the current through a conductor is directly proportional to the potential difference across it, provided the temperature and other physical conditions remain unchanged. This relationship is expressed by the equation V = IR, where V is voltage, I is current, and R is resistance.
Mark focus: Precise definition and topic focus.
Question 2
A Ohm's Law question uses an unfamiliar context. What should the answer do before adding detail?
Answer: It should name the process, variable, equation, particle model, or evidence being tested, then explain the result using precise scientific vocabulary.
Mark focus: Method selection and command-word control.
Question 3
A student makes this mistake: "Applying Ohm's Law to non-ohmic conductors. Ohm's Law only applies to components with a constant resistance, like a resistor at a constant temperature. It does not apply to filament lamps or diodes." What should their next repair task be?
Answer: Do one Ohm's Law question and review the mistake type.
Mark focus: Error correction and next-step practice.
Ohm's Law flashcards
Core idea
What is the main idea in Ohm's Law?
Ohm's Law states that the current through a conductor is directly proportional to the potential difference across it, provided the temperature and other physical conditions remain unchanged. This relationship is expre...
Common mistake
What mistake should you avoid in Ohm's Law?
Applying Ohm's Law to non-ohmic conductors. Ohm's Law only applies to components with a constant resistance, like a resistor at a constant temperature.
Practice
What is one useful practice task for Ohm's Law?
Answer one Ohm's Law question and review the mistake type.
Exam board
How should you use board notes for Ohm's Law?
A key law in all GCSE Physics specifications (AQA, Edexcel, OCR). Understanding which components are ohmic and non-ohmic is crucial.
Common mistakes
- 1Applying Ohm's Law to non-ohmic conductors. Ohm's Law only applies to components with a constant resistance, like a resistor at a constant temperature. It does not apply to filament lamps or diodes.
- 2Rearranging the formula incorrectly. A common mistake is to write I = VR or R = VI.
- 3Forgetting the condition that physical conditions (like temperature) must be constant. The resistance of many components changes with temperature.
Ohm's Law exam questions
Exam-style questions for Ohm's Law with mark-scheme style solutions and timing practice. Aligned to AQA, Edexcel, OCR, WJEC, Eduqas, CCEA, Cambridge International (CIE), Pearson Edexcel International, OxfordAQA International, SQA, IB, AP specifications.
Ohm's Law exam questionsGet help with Ohm's Law
Get a personalised explanation for Ohm's Law from the StudyVector tutor. Ask follow-up questions and work through problems with step-by-step support.
Open tutorFree full access to Ohm's Law
Sign up in 30 seconds to unlock step-by-step explanations, low-focus question cards, instant feedback and Play routes — completely free, no card required.
Try one low-focus question
Unlock Ohm's Law low-focus cards
Get instant feedback, step-by-step help and a calmer first run — free, no card needed.
Start free low-focus cardsAlready have an account? Log in
Step-by-step method
Step-by-step explanation
4 steps · Worked method for Ohm's Law
Core concept
Ohm's Law states that the current through a conductor is directly proportional to the potential difference across it, provided the temperature and other physical conditions remain unchanged. This rela…
Frequently asked questions
What is an ohmic conductor?
An ohmic conductor is a component that obeys Ohm's Law. Its resistance is constant, so the graph of voltage against current is a straight line through the origin.
What is the relationship between current and voltage in Ohm's Law?
Current is directly proportional to voltage. This means if you double the voltage, you double the current, as long as the resistance stays the same.