Drift Velocity

Question 1

What are the charge carriers in a wire?

Answer 1

free electrons (sometimes called conduction electrons)

Question 2

What are the charge carriers in gases and liquids?

Answer 2

ions

Question 3

How can a spark be caused in a gas?

Answer 3

when a high enough voltage is provided electrons can be ripped out giving ions. This is shown by a spark.

Question 4

What is the mean drift velocity?

Answer 4

the average velocity of the charge carriers

Question 5

What do elecrons exhibit with no pd in a wire?

Answer 5

random motion (random thermal motion ), this is due to the electric field

Question 6

What happens to the charge carriers when pd is provided?

Answer 6

They drift one way

Question 7

What is the equation for current in terms of drift velocity?

Answer 7

I = nAvq 
where 
I = current 
n = number of charge carriers 
A = cross sectional area 
v = mean drift velocity 
q = charge on charge carriers

Question 8

What does the number of charge carriers depend on?

Answer 8

depends on the material.

Question 9

What does the number of charge carriers determine?

Answer 9

The ability to conduct

Question 10

How can the ability to conduct be changed?

Answer 10

By changing temperature or adding/removing impurity atoms