Chapter 16: Q9Q (page 443)

The balloon in Fig. 16–48 was rubbed on a student’s hair. Explain why the water drip curves instead of falling vertically.

Short Answer

Expert verified

The water drip curves instead of falling vertically due to the electrostatic force of attraction between the charged balloon and the charge of opposite polarity induced on the stream of water.

Step by step solution

Understanding charging by induction

When a charged object induces a charge on another uncharged object without actually coming in contact with it, the process is termed as charging by induction. The charges developed on the uncharged body are known as induced charges.

Explanation for curving of water drip

When the balloon is rubbed on the student’s hair, it gets charged due to rubbing. When this charged balloon is brought near the water drip, the charges get induced in the water stream. Consequently, the charges of the water that has a polarity opposite to that on the balloon start moving to the face of the water stream, which is closer to the balloon due to the electrostatic force of attraction between the charges.

The charges that are accumulated on the closer face of the water stream cannot move out of it. As a result of the accumulation of charges of opposite polarity on the closer face of the water stream, it gets attracted toward the balloon. It thus follows a curved path instead of falling vertically.