When a plastic comb is placed next to a small piece of aluminium foil hanging from a nylon thread, the foil is repelled by the comb. Why is this?
The comb is charged and the foil is uncharged.
The comb is uncharged and the foil is charged.
The comb and the foil have charge of opposite signs.
The comb and the foil have charge of the same sign.
