Module 4 - Electricity

Question 1

What is current?

Answer 1

the rate of flow of charge

Question 2

What direction does conventional current flow?

Answer 2

positive to negative

Question 3

What are ions?

Answer 3

charge carriers

Question 4

What is an electrolyte?

Answer 4

a substance containing ions that conducts electricity

Question 5

Define mean drift velocity.

Answer 5

average speed of electrons flowing towards the positive terminal

Question 6

What is potential difference?

Answer 6

the work done between two points to move a unit charge between those two points

Question 7

Define an ohm.

Answer 7

a component has a resistance of 1 ohm if a potential difference of 1 volt makes a current of 1 amp flow through it

Question 8

Describe, with a reason, the connection between temperature and resistivity in (a) a metal, and (b) a semiconductor.

Answer 8

(a) resistivity increases as temperature increases because heating the metal increases the kinetic energy of the ions which causes them to vibrate and makes them collide with the lattice more often
(b) resistivity decreases as temperature increases because it causes more charge carriers to be released

Question 9

What is an Ohmic conductor? What is its correlation between current and potential difference?

Answer 9

a conductor that obeys Ohm’s law so as long as external factors stay constant, current is proportional to potential difference