Charging materials by friction
4 marks · NormalDescribe an experiment to investigate how a balloon can be charged by friction and tested for its charge. Include at least three steps and identify the expected result.
Describe the steps needed to charge the balloon by friction.
Explain how to test if the balloon is charged.
State what you would observe if your test is successful.
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) Rub the balloon vigorously with wool or a cloth for several seconds. Ensure that only the balloon and cloth touch during rubbing.
(b) Bring the balloon near small pieces of paper or to a wall to see if it is attracted.
(c) The balloon attracts (lifts) the paper or sticks to the wall.
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Rub balloon with a cloth or wool/fur.
M1 (a) · 1 mark · Ensure vigorous rubbing and that only balloon and cloth touch each other.
M1 (b) · 1 mark · Bring balloon near small pieces of paper or to a wall.
A1 (c) · 1 mark · States that the paper moves/is lifted or balloon sticks to the wall.
Worked solution
a) Rub the balloon firmly with a woolen cloth or jumper for at least 10 seconds. Make sure not to touch any other object during this time.
b) Bring the rubbed part of the balloon near small, dry pieces of paper.
c) The paper pieces will jump up to the balloon, showing it is charged.