Capactor as static electricity generator

[deval vyas]

Suppose I first charge a capacitor so that one plate is positively charged and another negatively. Now I remove the charging source and ground only one of the terminals say negative terminal, will there be a net positive charge in the capacitor that can be detected by a pith ball?
Can a capacitor be used as static electricity generator?

 

[Nidum]

Early static electricity experiments , Leyden jar , electrophorus

 

[anorlunda]

Yes you can do it. But the ball will only charge to the capacitor voltage. A bigger capacitor at the same voltage will not charge the ball any higher.