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 .