9702 · 9.3
Resistance and resistivity
In this lesson, we'll explore **resistance** and **resistivity**, fundamental concepts that define how materials interact with electric current. Understanding these allows us to predict circuit behaviour and design components ranging from simple wires to sophisticated sensors. Get ready to visualise the flow of charge and the forces that impede it! This pilot aligns with **Senpai Corner** AS notes (2025–2027) for topic **9.3**.
Need to know
What you need to know
- Resistance, R of a conductor is the opposition to an electrical current.
- The higher the resistance of a conductor the more work needs to be applied to push the same amount of current through a conductor (Think friction when pushing a box).
- Resistance is measured in ohms, Ω.
- Ohm’s Law states that the potential difference (V) is directly proportional to the Current (I) that flows through a conductor. 𝑅 = 𝑉 𝐼.
- This law is only obeyed provided that the temperature and other physical properties remain constant and that the conductor is ohmic.
Explanation
Resistance and resistivity
- Resistance, R of a conductor is the opposition to an electrical current.
- The higher the resistance of a conductor the more work needs to be applied to push the same amount of current through a conductor (Think friction when pushing a box).
- Resistance is measured in ohms, Ω.
- Ohm’s Law states that the potential difference (V) is directly proportional to the Current (I) that flows through a conductor. 𝑅 = 𝑉 𝐼.