Two Insulators in Contact?

📌 CONCEPT: When two insulators, such as a glass rod and an ebonite rod, are brought into contact and separated, the process results in the ebonite rod being negatively charged due to the transfer of electrons.

📐 RULE / FORMULA: The principle of conservation of charge applies, which states that the total charge remains constant, and the transfer of electrons from one body to another occurs until equilibrium is reached.

💡 WORKED EXAMPLE: Suppose we bring a glass rod and an ebonite rod into contact for 10 seconds. During this time, electrons from the ebonite rod transfer to the glass rod, causing the ebonite rod to become negatively charged. After separation, the glass rod will be positively charged, and the ebonite rod will be negatively charged.

⚠️ COMMON MISTAKE: Students often mistakenly assume that the glass rod will remain neutral, whereas in reality, it will become positively charged due to the transfer of electrons from the ebonite rod.