The correct option is (c).
Explanation
The transfer of electric charge depends on the material properties of the medium connecting charged objects. Materials are classified as conductors (which allow charge to flow freely) and insulators (which inhibit charge flow). The process of transferring charge from a charged object to the earth is known as earthing.
Statement-wise Analysis:
- Statement 1 is Incorrect: Rubber is an electrical insulator. In insulators, electrons are tightly bound to atoms and do not move freely. Therefore, electrical charge cannot be effectively transferred from one object to another through a rubber band.
- Statement 2 is Correct: Metals, such as a paper clip, are electrical conductors. They possess free electrons that move easily throughout the material, allowing electrical charge to be transferred from a charged object to another through the clip.
- Statement 3 is Correct: An electroscope detects charge based on the repulsion between two foil strips. When a human hand touches the metal clip of a charged electroscope, the body acts as a conductor. The excess charge flows from the electroscope through the body to the earth (grounding). As the foil strips lose their charge, the repulsive force vanishes, causing them to collapse.
Key Takeaway:
Electrical charge flows through conductors (like metals) but not through insulators (like rubber). Earthing is the process of discharging a charged body by connecting it to the earth, often resulting in the collapse of electroscope leaves.