Unit 3 Review ( Static electricity
1. Why is static electricity considered to be a charge and not a current ?
Because static electricity means not moving. And current moves therefore it's a charge.
5. Electroscope with a negative charge. An object with an unknown charge is brought close to the electroscope. And they attract . Dose the object have a positive charge or - ?
A + charge
7. A thundercloud has a negative charge and an object an object on the ground has a + charge . Will the Lightning discharge be form the cloud to the ground or from the ground to the cloud ?
Cloud to object .
4. What is an electroscope ?
Is an early electric instrument to determine the polarity of an object.
8. Name two Devices that are used for lightning protection.
Lightning rod and a lightning arrester .
2. If electrons are removed from an object is the object + charged or - charged ?
Object would have a+ charge .
10. What special property dose selenium have that makes it useful in a copy machine .
Selenium is a semi conductor material that changes its conductivity with a change of light intensity.
9. What type of material is used to coat the aluminum drum of a copy machine ?
Uses an aluminum drum coated with selenium .
6. Can one thundercloud contain both negative and positive charges ?
Yes positive and negative charges can be contained in the same in the same cloud . ( not at the same time tho )
3. Why do static charges accumulate on insulator materials only ?
because the electrons need to be stationary and only insulators do that .