Static Electricity Flashcards
Explain charging by friction.
When certain insulating materials are rubbed against each other they become electrically charged. Negatively charged electrons are rubbed off one material and on to the other. The material that gains electrons becomes negatively charged. The material that loses electrons is left with an equal positive charge.
How do electrically charged objects interact, and by what type of force?
Oppositely charged objects attract, while negatively charged objects repel, an example of a non-contact force.
Give 3 examples of how static charge can be demonstrated.
- A charged rod can ‘pick up’ a small piece of paper.
- A charged balloon can ‘stick’ to a wall.
- A charged rod can attract a stream of water.
Describe sparking and how it can result from an increase in charge in an isolated object.
The greater the charge on an isolated object, the greater the potential difference between the object and earth. If the potential difference becomes high enough a spark may jump across the gap between the object and any earthed conductor which is brought near it.
Describe electric fields, and how they lead to electric forces.
A charged object creates an electric field around itself. The electric field is strongest close to the charged object. A second charged object placed in the field experiences a force. The force gets stronger as the distance between the objects decreases.
In what direction do arrows point in electric field diagrams?
From positive to negative charge.
