Q.No.12.3: - How can you identify that which plate of a capacitor is positively charged?

Q.No.12.3: - How can you identify that which plate of a capacitor is positively charged?

Ans: - For this purpose we can use Gold Leaf Electroscope (GLE). We bring the disc of a positively charged electroscope close to the plate of the capacitor. If the divergence of the gold leaf increases, then the plate is positively charged and if the divergence in the leaf decreases, then the plate is negatively charged.

                                                  Or

Rub together a plastic rod and a piece of fur, both initially uncharged, the rod acquires a negative charge (since it takes electrons from the fur) and the fur acquires a positively charge of the same magnitude ( since it has lost as many electrons as the rod has gained). Now bring the plastic rod to one of the capacitors plate is there is a repulsion between the plastic rod and the capaticor’s plate then it means that the plate is negatively charged and the other has positive charge and vice versa.