Unit 2 - Conduction of Electricity

Question 1

What is the unit of charge

Answer 1

Coulomb (C)

Question 2

Which direction is Conventional current flow?

Answer 2

positive to negative

Question 3

Which direction is electron/charge flow?

Answer 3

negative to positive

Question 4

What is meant by the term drift velocity of the electrons in the wire

Answer 4

average speed of electron passing through a wire in the presence of an electric field

Question 5

How to derive the drift velocity equation
I = nAve

Answer 5

n = number of charge carriers per m^3
nV = total number of charge carriers
nVe = total charge = Q

V = length x Area so
Q = nVe –> Q = nLAe

Q = ixt , i = q/t (q equals to nLAe, so
i = nlae / t

(speed = dist/time -> v=L/A
so L = vt)

So i = nvtAe/t (t cancels out so i = nvAe