A-LEVEL PHYSICS: Introductory: Drift Velocity & Derivation of I = nAqV (or I = nevA) Flashcards
Metals are…
Conductors.
Metals are Solids that Contain ___ ___ that make them…
Delocalised Electrons, Electric Conductors.
What is Responsible for Current in Metals?
Delocalised Electrons.
Why do the Delocalised Electrons in Metals Move Randomly throughout the Metallic Structure?
Because they Share in the Thermal Energy in the Metal.
As Long as Electrons have ___, they Will Not be ___.
Energy, Stationary. (Even when in Fixed Positions, eg in a Solid Metal, the Metal Ions Will Vibrate.)
What is the Typical Thermal Velocity of an Electron at Room Temperature?
10^5 m/s
Since Electrons have Random Motion, Movement in Different Directions Will…
Cancel Out.
What Causes a ‘Net Flow of Charge’?
When Electrons have Net Movement in the Same Direction. (They Drift in One Direction).
When you Connect a Battery, what Happens?
When you Connect a Battery, it Provides a Potential Difference (Voltage) to the Circuit, causing a Net Flow of Charge (a Current).
Net Flow of Charge is When…
Electrons Drift in One Direction.
When you Connect a Battery, it Provides a Potential Difference (Voltage) to the Circuit, causing a Net Flow of Charge (Current).
The Electrons will ___ in One Direction.
Hence, we Define this as…
Drift.
Hence, we Define this as ‘Drift Velocity’.
This Velocity superimposes Over the Thermal Velocity of the Electrons causing Random Motion, giving the Charge a Net Flow (Current), where all Electrons Drift in the Same Direction.
What are the 2 Equations for the ‘Drift Velocity’ Topic? (2)
- I = nAqv
- I = nevA
