After combing his hair,Sameer kept the comb on the table where some pieces of paper were lying. He observed that the plastic comb attracted small pieces of paper. He was surprised to see this and asked his teacher about it. His teacher explained to Sameer that matter contains charged particles and that an electrically charged object can attract an uncharged object. Specifically,upon rubbing with dry hair,a comb acquires an electric charge,which then attracts the pieces of paper.
$(a)$ Give any other practical application of this.
$(b)$ What kind of qualities are shown by Sameer?