2.1 Conduction

Question 1

How do you prove I=nAve?

Answer 1

1) Find the volume
- Length = Velocity x time (L = vt)
∴ Volume = Cross sectional area x Velocity x time (V = Avt)
2) Find the number of electrons
- Num Electrons = electron density per metre x Avt (Num electrons =nAvt)
3) Find the charge
- Charge = nAvt x charge of 1 electron (1.6 x 10^-19) (Q = nAvte)
4) Find current
Current = Charge/ time (I = ΔQ/Δt)
∴ I = nAvte/t = nAve

I = nAve

Question 2

What is the electric current?

Answer 2

The rate of flow of electric charge (I = ΔQ/Δt)

Question 3

What is the efficiency of a system?

Answer 3

100 x useful work (or energy) out / work (or energy) put in