1. A positively charged glass rod is bought close to a suspended metal needle. What can we say about the charge on the needle given that the needle is :

a) attracted ?

b) repelled?

2. How would you determine the sign of a charge on a body using an electroscope? 

3. You are given two metal spheres mounted on portable insulating supports. How would you give them equal and opposite charges ? You may use a glass rod rubbed with silk but you may not touch it to the spheres. 

4. You are given two metal spheres mounted on portable insulating supports. How would you give them identical charges? You may use a glass rod rubbed with silk but you may not touch it to the spheres.