Questions: Static Electricity and Charge Transfer

Question 1

How does charging by induction differ from charging by conduction?

• A. Induction requires rubbing; conduction does not
• B. Induction requires direct contact; conduction does not
• C. Induction separates charges without contact; conduction transfers charge through contact
• D. There is no difference

Answer: (C)

In conduction, charge transfers through direct touching. In induction, a nearby charged object causes charge separation in a neutral object without ever touching it.

Question 2

A lightning rod protects a building by providing a path for charge to flow safely into the ground.

• T. True
• F. False

Answer: True

The lightning rod is a conductor connected to the Earth. It provides a low-resistance path for the lightning's charge to flow into the ground, bypassing the building.

Question 3

Why do you sometimes get a shock when touching a metal doorknob after walking across a carpet?

Model answer: Walking on the carpet transfers electrons between your shoes and the carpet (charging by friction), building up static charge on your body. When you touch the metal doorknob (a conductor), the charge rapidly discharges through the small gap, creating a spark.

Friction between your shoes and the carpet transfers electrons, giving you a net charge. The charge cannot escape through the insulating carpet but discharges instantly when you touch a conductor like a doorknob.