Brass rods cannot be charged by rubbing because they are considered to be conductors. Conductors are materials that allow electric charges to flow through them easily. When a brass rod is rubbed, the charges generated by friction are quickly dispersed throughout the rod, preventing any significant build-up of charge.
No, not all rubbing materials can charge a brass rod. Brass rods are typically made of copper and zinc, which have a high conductive ability. Materials that have a higher degree of electronegativity, such as glass or rubber, are better suited for charging objects through friction.
Insulating a brass rod can help to prevent the dispersal of charges generated by rubbing, but it is still unlikely to result in a significant build-up of charge. Insulators do not allow charges to flow through them easily, but they can still transfer charges through direct contact with a conductor.
Materials that charge easily through rubbing tend to have a higher degree of electronegativity, meaning they have a greater tendency to attract or hold on to electrons. This allows them to easily transfer charges to and from other materials, resulting in a build-up of charge. Brass, on the other hand, has a lower electronegativity and is therefore less effective at generating and transferring charges through friction.
Yes, brass rods can be charged through other methods such as induction or contact with a charged object. Induction involves bringing a charged object near the brass rod, causing the charges within the rod to rearrange and create a temporary charge. Contact with a charged object can also transfer charges to the brass rod, resulting in a build-up of charge.