PHYSICS

 TRIBO-ELECTRIC SERIES  The series in which the substances are arranged according to their tendency to lose or gain electrons on rubbing each other. The higher the position of the substance, it has the tendency to lose electrons and to gain positive charge on rubbing. The series of common substances  follows, Air Human hair Rabbit's fur Glass Hair Silk Paper Cotton Steel Wood Amber Rubber balloon Plastic wrap Ebonite Example: When glass rod is rubbed with silk, the rod loses electrons and get positively charged whereas silk gains electrons from the rod and gets negatively charged. Please check the position of glass in relation with silk. Glass is placed above silk.