Forces between charged and uncharged objects
3 marks · EasyA student rubs a plastic rod with a woolen cloth.
State the type of force observed if she then brings the charged rod close to an uncharged small piece of paper.
Explain why this force occurs.
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.
Show answer
(a) Attractive force.
(b) —
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States that an attractive force is observed
M1 (b) · 1 mark · Explains that the charged rod induces opposite charges on part of the uncharged paper
M2 (b) · 1 mark · Explains that this results in attraction between the rod and the paper
Worked solution
a) Attractive force.
b) The charged rod induces a redistribution of charges in the uncharged paper so that the side closer to the rod has an opposite charge. Opposite charges attract, so the paper is attracted to the rod.