Unit 2 - Static Charge Flashcards
Why doesn’t a metal ruler become charged when rubbed against a cloth?
Metals conduct free electrons.
A cloth and a plastic ruler are rubbed together. Why does the ruler become positively charged?
The ruler has lost electrons or transferred electrons to the cloth.
Why does your hair stand on end when you are touching a Van der Graaf Generator?
Each hair strand has the same charge (positive or negative) and like charged repel each other.
Why do you need to stand on a plastic tray to become charged when on a Van der Graaf generator?
Plastic is an insulator and so the charge can not be earthed (electrons can not move away from you to earth or on to you from Earth.)
Two insulating materials are rubbed together. As a result forces act on the two materials . Describe the forces acting on the two insulators.
The forces will be equal in size and act in opposite directions (opposite charges attract).
Two insulating materials with the same charge are moved close to each other. Describe the forces acting on the materials.
The forces will be equal in size and act in opposite directions, like charges repel each other.
How is static charge created?
The rubbing together of two insulating materials causing a transfer of electrons.
