8.1 Current and charge

Question 1

Define electric current and its unit

Answer 1

The rate of flow of charge
1 coulomb 1C / 1 ampere second 1 A s

Question 2

Define the equation for electric current

Answer 2

Change in charge transferred ÷ change in time, the amount of charge passing a given point in a circuit per unit time

Question 3

State the 2 types of electrical charge

Answer 3

Positive and negative

Question 4

Define a charge carrier and state some examples

Answer 4

Any particle that has an electric charge. Examples are protons, electrons, copper^2+ ion and sodium^+ ion

Question 5

Define net charge

Answer 5

The total charge after taking into account both the positive and negative charges

Question 6

How is net charge calculated

Answer 6

Net charge in coulombs = number of electrons ( added or removed ) x elementary charge

Question 7

Define elementary charge

Answer 7

Charges measured against the constant, e

Question 8

State what elementary charge is equal to

Answer 8

1.60 x 10^ -19 coulombs, the charge in one proton