Uses of static electricity
3 marks · EasyState what happens to the pieces of paper when a charged plastic ruler is brought close to them.
Explain why this happens.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) The pieces of paper are attracted to the ruler and move towards it.
(b) The charged ruler causes electrons in the paper to move, inducing opposite charges on the paper closest to the ruler, so the paper and ruler attract.
Common mistakes: Saying the paper becomes charged by contact.; Not mentioning movement of electrons.
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States that the paper is attracted to or moves towards the ruler.
M1 (b) · 1 mark · Explains that the ruler induces a charge on the paper.
A1 (b) · 1 mark · Explains that this induced charge causes the attraction.
Worked solution
a) The small pieces of paper move towards and stick to the ruler. b) The charged plastic ruler causes the electrons in the paper to move within the paper, inducing a charge on the side closest to the ruler. This results in a net attraction between the positively charged ruler and the negative induced charge in the paper.