When an electroscope is charged, its two leaves repel each other and remain at an angle. What balances the electric force of repulsion so that the leaves don’t separate further?
Gravity tries to pull the leaves down to a vertical position.
The balance of the electric force of repulsion in an electroscope is maintained by the force of gravity acting on the leaves. As the leaves repel each other due to the buildup of charge, they try to move further apart. However, gravity pulls the leaves downward, opposing the electric repulsion and preventing them from separating completely.
To understand this concept further, let's break it down step by step:
Step 1: When an electroscope is charged, it means excess charges (either positive or negative) are transferred to the metal rod or plate inside the electroscope. These charges distribute throughout the electroscope and cause the metal leaves to acquire the same charge.
Step 2: Like charges repel each other, so the leaves, now having the same charge, create an electric force of repulsion between them. This repulsive force tries to push the leaves apart.
Step 3: At the same time, the Earth's gravity comes into play. Each leaf has a mass and is pulled downward by gravity. The force of gravity tries to bring the leaves closer together.
Step 4: The equilibrium point is reached when the electric force of repulsion pushing the leaves apart is balanced by the force of gravity pulling them together. At this point, the leaves remain at a particular angle, and no further separation occurs.
It's important to note that the angle at which the leaves settle can provide rough information about the magnitude of charge on the electroscope. The greater the charge, the wider the separation of the leaves, as the electric force of repulsion becomes stronger relative to gravity.
In summary, the balance between the electric force of repulsion and gravity ensures that the leaves of an electroscope neither come together nor separate further, resulting in a stable angle.