Assessment: Electricity

A positively charged rod is brought near a negatively charged sphere (without touching). What happens?

Which of these is the best electrical insulator?

Two charges of +6 × 10⁻⁶ C and +1 × 10⁻⁶ C are 0.3 m apart. Find the force between them (k = 9 × 10⁹ N·m²/C²).

Find the total charge of 1 × 10¹⁵ electrons (e = 1.6 × 10⁻¹⁹ C).

A plastic rod is rubbed with a wool cloth, and the rod becomes negatively charged. What happened to the wool?

Two charges of +2 × 10⁻⁶ C and +3 × 10⁻⁶ C experience a force of 0.054 N. Find their separation r (k = 9 × 10⁹ N·m²/C²).

Why does a plastic comb, after being rubbed on dry hair, pick up small pieces of paper?

A person touching the dome of a Van de Graaff generator becomes charged, making their hair stand on end. Which method of electrification is this?

Two EQUAL charges are 0.1 m apart and repel each other with a force of 0.9 N. Find the magnitude of each charge (k = 9 × 10⁹ N·m²/C²).

A charged sphere has a charge of +4.8 × 10⁻¹⁸ C, meaning it is missing some electrons. Find how many electrons are missing (e = 1.6 × 10⁻¹⁹ C).