Want to know how current and voltage behave in different... Show more
Physics254 views·Updated Jun 1, 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.
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Physics254 views·Updated Jun 1, 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... Show more
1
of 2Sign up to see the content. It's free!
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- Join milions of students
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
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...
What is the Knowunity AI companion?
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.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
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
2Most popular content in Physics
9Most popular content
9Can't find what you're looking for? Explore other subjects.
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