Charging method that uses friction:

**The reasoning** This question is testing your knowledge of **electrostatic charging methods**. When you rub two materials together (like a plastic comb through dry hair, or a balloon on a sweater), electrons are transferred from one material to the other through direct contact and rubbing. This process is literally called **charging by friction** (or triboelectric charging). The friction creates intimate contact between surfaces, allowing electrons to move from the material that holds them loosely to the one that attracts them more strongly. One object becomes negatively charged (gains electrons), the other becomes positively charged (loses electrons). **Why the wrong options tempt you** - **A) Conduction** involves touching a charged object to a neutral one to share charges — no rubbing needed - **B) Induction** charges an object *without* touching it at all, using only the influence of a nearby charged object - **D) Earthing** removes excess charge by connecting to the ground — it's not a charging method but a discharging one **Quick takeaway** When you see "friction" and "rubbing" together in charging, the answer is literally **friction** — it's the most direct method where contact + movement = charge transfer!