Vicky combs her hair with a plastic hair comb - Edexcel - GCSE Physics - Question 6 - 2012 - Paper 1

Vicky's hair has become charged as a result of losing electrons to the comb during the combing process. This transfer of electrons happens due to friction between the hair and the comb. Consequently, her hair, now lacking electrons, acquires a positive charge.

The foil becomes negatively charged because it is attracted to the negatively charged comb, resulting in the foil electrons repelling each other. Therefore, an arrow should be drawn towards the bottom of the foil to indicate that the foil is negatively charged.

The metal comb does not pick up the metal foil because it does not carry any static charge. Since both the comb and the metal foil are neutral, there is no electrostatic attraction to cause the foil to adhere to the comb.

Using an electrostatic paint sprayer has several benefits. Firstly, the negatively charged paint particles are attracted to the positively charged metal object, ensuring better coverage and less overspray. This leads to a more efficient paint application and minimizes waste. Additionally, the charged paint particles can reach into crevices more effectively than uncharged paint, providing a more uniform coating.