A balloon and a section of a wall both have neutral charges, as shown below.

Question

A student rubs his hair on the balloon, giving it a negative charge. How will the charges be arranged in the wall when it is placed near the negatively changed balloon?

Answer 1

When the negatively charged balloon is brought near a neutral wall, it induces a redistribution of charges in the wall due to electrostatic induction.

Here's how the charges will be arranged:

1. Negative Charges in the Wall: The negative charge from the balloon will repel the electrons in the wall. As a result, the electrons in the wall will move away from the balloon, creating a deficiency of electrons (or a positive charge) on the side of the wall closest to the balloon.

2. Positive Charges in the Wall: Conversely, the side of the wall that is farthest from the balloon will have a relatively higher concentration of electrons since they are repelled away from the balloon. This creates a region of positive charge on the side of the wall nearest to the balloon, and the region farthest from the balloon retains its negative charge.

In summary, when the negatively charged balloon is placed near the neutral wall, the side of the wall closest to the balloon becomes positively charged (due to the deficiency of electrons), while the side of the wall farthest from the balloon remains neutral or could slightly accumulate more electrons. This results in a separation of charges in the wall, leading to a polarized effect.