0625/12 Physics Oct Nov 2024 Online Test | Cambridge IGCSE MCQ

A student investigates the electrostatic charges on three objects P, Q and R.
The student places object P on the insulated pan of a balance and notes the reading on the balance.
The student then holds object Q a small distance above object P and notes the reading on the balance.
Finally, the student holds object R the small distance above object P and notes the reading on the balance.
The student’s observations are shown.
Which row gives possible charges that explain…