Want to know how current and voltage behave in different...
Physics254 views·Updated 3 Jul 2026·2 pagesUnderstanding I/V Characteristics: Physics Practical
Lucía @luttior
1
of 2
Setting Up Your I/V Characteristics Investigation
You'll be investigating how current and voltage relate in different circuit components using some basic equipment. Your circuit needs a battery, the component you're testing, an ammeter (measures current through the component), a voltmeter (measures potential difference across the component), and a variable resistor to change the values.
The method is straightforward: record the voltage and current readings, then adjust the variable resistor to get different values. Don't forget to reverse the battery direction halfway through - this gives you negative readings and shows the complete picture of how your component behaves.
When you plot your results for a resistor, you'll get a straight line through zero. This proves that current is directly proportional to potential difference - a key characteristic of ohmic conductors. The line stays straight even when you reverse the battery direction.
Top Tip: Keep your circuit connected for short periods only, as heating can change your resistor's behaviour and mess up your results.
2
of 2
Testing Different Components
Temperature matters hugely in these experiments. If your resistor gets hot from being connected too long, your straight-line graph will curve instead - the resistance increases with temperature and ruins the proportional relationship.
Filament lamps behave completely differently. Your graph won't be a straight line because as current increases, the filament heats up and its resistance increases. This creates a curved graph that shows current is not proportional to potential difference.
Diodes need special care because they're easily damaged by high current. Always add an extra resistor to protect the diode and keep currents low. You'll need a sensitive milliammeter instead of a regular ammeter since the currents are so small.
Exam Alert: Remember that only resistors at constant temperature give straight-line graphs - filament lamps and diodes create curved graphs due to their changing resistance.
We thought you’d never ask...
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Similar content
Most popular content: Resistor
1Most popular content in Physics
9G
PhysicsGCSE Physics - Energy stores and Systems
Pl-Energy topic to revise for GCSE
101,3752
PhysicsForces and Motion Overview
Explore key concepts in Forces and Motion, including Hooke's Law, velocity, acceleration, and the principles of moments. This summary covers essential topics such as the relationship between force and extension, terminal velocity, and the impact of safety devices in physics. Ideal for AQA Physics Unit 5 revision.
109,195872
C
PhysicsConservation of energy- energy types and stores
Build a strong foundation in physics with these easy flashcards covering key concepts and principles.
96391
PhysicsPhysics Paper 2 Essentials
Master key concepts for AQA Combined Physics Paper 2, including electromagnetic waves, mechanics, forces, and motion. This comprehensive summary covers essential topics like wave properties, Newton's laws, and the motor effect, ensuring you're well-prepared for your exam.
1116,074940
P
PhysicsPhysics Made Easy: Essential Concepts for Grade 10 Students
Master the fundamentals of physics with this comprehensive flashcard set designed specifically for grade 10 students. Learn key concepts and principles in an easy and engaging way!
104531
PhysicsGCSE Physics Practical Experiments
Explore essential GCSE Physics practicals for AQA, covering key concepts such as Hooke's Law, wave properties, thermal insulation, and electrical circuits. This comprehensive guide includes step-by-step procedures, variables, and safety considerations for each experiment, ensuring a thorough understanding of practical applications in physics.
1011,409477
PhysicsPhysics paper 2 notes
physics aqa gcse paper 2 combined higher notes
101,24211
Physicsphysics paper 2 foundation notes
aqa combined science physics paper 2 foundation notes
101,33138
I
PhysicsIdentifying Types of Energy Stores
Learn to recognize different energy stores including kinetic, gravitational potential, chemical, and thermal in various objects and systems.
S32380
Most popular content
9
SociologySociology of Education Overview
Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.
12102,9093,041
SociologySociology of Families: Comprehensive Revision
Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.
1273,6962,307
CriminologyCriminology: Crime & Punishment Overview
Comprehensive mindmaps covering key concepts in the Crime and Punishment topic for WJEC Criminology Unit 4. This resource includes detailed insights into the Criminal Justice System, crime prevention strategies, sentencing models, and the roles of various agencies. Ideal for A-Level revision, ensuring you grasp essential theories and legislative processes to excel in your exams.
1254,8811,059
SociologyComprehensive Crime & Deviance Overview
Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.
1251,6621,399
C
BiologyCell Biology and Cell structure
cell structures
93,2590
CriminologyWJEC Unit 4 Criminology
Criminology unit 4 detailed revision note
127,161125
English LiteratureAn Inspector Calls: Character Insights
Explore in-depth analysis and key quotes for characters in J.B. Priestley's 'An Inspector Calls'. This resource covers Gerald Croft, Inspector Goole, Sheila Birling, Mrs. Birling, Eric Birling, and Eva Smith, focusing on themes of class, gender roles, and social responsibility. Ideal for students aiming for Grade 8 and above.
1025,437907
CriminologyCriminology Theories Overview
Explore key criminology theories and their implications on crime and deviance. This comprehensive summary covers biological, psychological, and sociological perspectives, including labelling theory, right realism, and the impact of social campaigns on policy development. Ideal for A-Level criminology students seeking to understand the complexities of criminal behaviour and the factors influencing crime prevention strategies.
129,766210
SociologySociological Theories Overview
Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.
1231,468846
Students love us — and so will you.
4.6/5App Store
4.7/5Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan SiOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha KlichAndroid user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
AnnaiOS user
Physics254 views·Updated 3 Jul 2026·2 pagesUnderstanding I/V Characteristics: Physics Practical
Lucía @luttior
Want to know how current and voltage behave in different electrical components? This practical investigation shows you how to measure and graph the relationship between current and voltage in resistors, filament lamps, and diodes - essential skills for your physics...
1
of 2
Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Setting Up Your I/V Characteristics Investigation
You'll be investigating how current and voltage relate in different circuit components using some basic equipment. Your circuit needs a battery, the component you're testing, an ammeter (measures current through the component), a voltmeter (measures potential difference across the component), and a variable resistor to change the values.
The method is straightforward: record the voltage and current readings, then adjust the variable resistor to get different values. Don't forget to reverse the battery direction halfway through - this gives you negative readings and shows the complete picture of how your component behaves.
When you plot your results for a resistor, you'll get a straight line through zero. This proves that current is directly proportional to potential difference - a key characteristic of ohmic conductors. The line stays straight even when you reverse the battery direction.
Top Tip: Keep your circuit connected for short periods only, as heating can change your resistor's behaviour and mess up your results.
2
of 2Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Testing Different Components
Temperature matters hugely in these experiments. If your resistor gets hot from being connected too long, your straight-line graph will curve instead - the resistance increases with temperature and ruins the proportional relationship.
Filament lamps behave completely differently. Your graph won't be a straight line because as current increases, the filament heats up and its resistance increases. This creates a curved graph that shows current is not proportional to potential difference.
Diodes need special care because they're easily damaged by high current. Always add an extra resistor to protect the diode and keep currents low. You'll need a sensitive milliammeter instead of a regular ammeter since the currents are so small.
Exam Alert: Remember that only resistors at constant temperature give straight-line graphs - filament lamps and diodes create curved graphs due to their changing resistance.
We thought you’d never ask...
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Similar content
Most popular content: Resistor
1Most popular content in Physics
9G
PhysicsGCSE Physics - Energy stores and Systems
Pl-Energy topic to revise for GCSE
101,3752
PhysicsForces and Motion Overview
Explore key concepts in Forces and Motion, including Hooke's Law, velocity, acceleration, and the principles of moments. This summary covers essential topics such as the relationship between force and extension, terminal velocity, and the impact of safety devices in physics. Ideal for AQA Physics Unit 5 revision.
109,195872
C
PhysicsConservation of energy- energy types and stores
Build a strong foundation in physics with these easy flashcards covering key concepts and principles.
96391
PhysicsPhysics Paper 2 Essentials
Master key concepts for AQA Combined Physics Paper 2, including electromagnetic waves, mechanics, forces, and motion. This comprehensive summary covers essential topics like wave properties, Newton's laws, and the motor effect, ensuring you're well-prepared for your exam.
1116,074940
P
PhysicsPhysics Made Easy: Essential Concepts for Grade 10 Students
Master the fundamentals of physics with this comprehensive flashcard set designed specifically for grade 10 students. Learn key concepts and principles in an easy and engaging way!
104531
PhysicsGCSE Physics Practical Experiments
Explore essential GCSE Physics practicals for AQA, covering key concepts such as Hooke's Law, wave properties, thermal insulation, and electrical circuits. This comprehensive guide includes step-by-step procedures, variables, and safety considerations for each experiment, ensuring a thorough understanding of practical applications in physics.
1011,409477
PhysicsPhysics paper 2 notes
physics aqa gcse paper 2 combined higher notes
101,24211
Physicsphysics paper 2 foundation notes
aqa combined science physics paper 2 foundation notes
101,33138
I
PhysicsIdentifying Types of Energy Stores
Learn to recognize different energy stores including kinetic, gravitational potential, chemical, and thermal in various objects and systems.
S32380
Most popular content
9SociologySociology of Education Overview
Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.
12102,9093,041
SociologySociology of Families: Comprehensive Revision
Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.
1273,6962,307
CriminologyCriminology: Crime & Punishment Overview
Comprehensive mindmaps covering key concepts in the Crime and Punishment topic for WJEC Criminology Unit 4. This resource includes detailed insights into the Criminal Justice System, crime prevention strategies, sentencing models, and the roles of various agencies. Ideal for A-Level revision, ensuring you grasp essential theories and legislative processes to excel in your exams.
1254,8811,059
SociologyComprehensive Crime & Deviance Overview
Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.
1251,6621,399
C
BiologyCell Biology and Cell structure
cell structures
93,2590
CriminologyWJEC Unit 4 Criminology
Criminology unit 4 detailed revision note
127,161125
English LiteratureAn Inspector Calls: Character Insights
Explore in-depth analysis and key quotes for characters in J.B. Priestley's 'An Inspector Calls'. This resource covers Gerald Croft, Inspector Goole, Sheila Birling, Mrs. Birling, Eric Birling, and Eva Smith, focusing on themes of class, gender roles, and social responsibility. Ideal for students aiming for Grade 8 and above.
1025,437907
CriminologyCriminology Theories Overview
Explore key criminology theories and their implications on crime and deviance. This comprehensive summary covers biological, psychological, and sociological perspectives, including labelling theory, right realism, and the impact of social campaigns on policy development. Ideal for A-Level criminology students seeking to understand the complexities of criminal behaviour and the factors influencing crime prevention strategies.
129,766210
SociologySociological Theories Overview
Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.
1231,468846
Students love us — and so will you.
4.6/5App Store
4.7/5Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan SiOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha KlichAndroid user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
AnnaiOS user