Question

an electroscope is a device that detects charge on objects that touch it or are brought near it. john rubs a piece of cotton fabric on a plastic rod and then touches the rod to the electroscope. what methods of charging does john use? john charges the rod through induction, then charges the electroscope through friction. john charges the rod through conduction, then charges the electroscope through induction. john charges the rod through friction, then charges the electroscope through induction john charges the rod through friction, then charges the electroscope through conduction.

Explanation:

• Charging by friction: When John rubs the cotton fabric on the plastic rod, electrons are transferred between the two materials due to friction. One material loses electrons (becomes positively charged) and the other gains electrons (becomes negatively charged).
• Charging by conduction: When the charged rod touches the electroscope, electrons can move from the rod to the electroscope (or vice - versa depending on the charge of the rod). This is because in conduction, charge is transferred through direct contact.

Answer:

John charges the rod through friction, then charges the electroscope through conduction.