Topic 2c- Static electricity and electrical fields

Question 1

What is static charge?

Answer 1

An electrical charge that cannot move.

Question 2

How is static charge created?

Answer 2

• Two insulating materials are rubbed together
• Friction causes negatively charged electrons to be taken from one and transferred to the other
• This results in one material being positively charged (it has lost electrons) and the other being negatively charged (the one that has gained electrons)

Question 3

What causes sparking?

Answer 3

• As electric charge builds up on one object, the potential difference between the object and the earth increases.
• If the potential difference becomes large enough, electrons can jump across the gap between the charged object and the earth creating a spark

Question 4

What is an electrical field?

Answer 4

An electrical field is created around any electrically charged object

Question 5

Explain sparking with electrical fields

Answer 5

• A high enough potential difference between a charged object and the earthed object results in a strong electrical field between the objects.
• The strong electrical field causes electrons in the air particles to be removed (ionisation).
• Although air is normally a conductor, when it is ionised charge can flow through it.
• This is the spark.