Question: Rub plastic ruler with your hair. Place it near running water from tap. You see that thin stream of water is deflected. Explain why?
Answer: Thin stream of water is deflected because of electrostatic induction when a charged plastic ruler is brought near it.
Explanation: When plastic ruler is rubbed with hair, it gets charged due to rubbing. When this ruler is brought near a running tap of water, opposite charges are created on it due to electrostatics induction. Since opposite charges attract each other, therefore the thin stream of water is attracted by the plastic ruler and seeming that the stream of water is deflected.
What is Electrostatic Induction?
A change in distribution of electrical charge in an object, caused by the influence of nearby charges is called electrostatic induction.
Another Experiment:
When a plastic comb (or plastic rod) is run through hair and then is brought near small pieces of paper, the comb attracts them.