static electricity

Question 1

Explain why when taking off fleece with shirt underneath the fleece becomes charged

Answer 1

fleece rubs against shirt (friction)
causing electrons to transfer between one to other (specific reference allowed)

Question 2

Explain why if a negatively charged student touches a metak tap they receive an electric shock

Answer 2

there is a potential difference between student and tap
which causes electrons to transfer from student to tap
which earths the charge (as tap is earthed)

Question 3

suggest why putting thin copper wires in carpet will reduce risk of electric shocks

Answer 3

copper has a low resistance
so lower build up of charge/smaller pd so no pd between student and tap

Question 4

If 2 ends of plastic are repelling, what 2 conclusions can be made about the forces acting on 2 ends

Answer 4

-they are repulsive
-they are equal in size