The electroscope is used to show electrostatic charge. When a charged rod is brought near the plate, the needle deflects. If you scrape the plate with the rod, it becomes charged and the needle remains deflected. The deflection decreases when you bring an object of opposite charge near the plate.
Set up time
Physics and Science Concepts
First, show the electroscope in resting stage. Then, charge a rod or other material by rubbing the object in a cloth. Place this near the plate of the electroscope and observe the deflection of the needle. To keep the needle deflected, scrape the plate with the charged object. A decrease in deflection occurs when an oppositely charged object is placed near the plate.