Physics · Oct / Nov 2025 · Paper 11 · Question 28

A student investigates electrostatic charge using a balloon and a cloth. The balloon and cloth are initially uncharged. The student rubs the balloon with the cloth. The balloon gains a negative charge of magnitude Q. The cloth becomes charged and a force acts between the balloon and the cloth. Which row correctly describes the magnitude and sign of the charge on the cloth and the type of force between the balloon and the cloth?

1. Amagnitude of charge on cloth: equal to Q; sign of charge on cloth: positive; type of force: attraction
2. Bmagnitude of charge on cloth: equal to Q; sign of charge on cloth: negative; type of force: repulsion
3. Cmagnitude of charge on cloth: greater than Q; sign of charge on cloth: positive; type of force: repulsion
4. Dmagnitude of charge on cloth: greater than Q; sign of charge on cloth: negative; type of force: attraction

As printed in the paper