Page 1 - Lesson notes- Methods of charging

SAI INTERNTIONAL SCHOOL
Class 8
Home Assignment
Subject- Physics
Ch- Some Natural Phenomena
Subtopic- Methods of Charging

Methods of charging an object:
1. Charging by rubbing(friction)
2. Charging by conduction
3. Charging by Induction

Charging by rubbing: In this method the material is charged by rubbing it
with another material. During this process electrons are lost by one material
which becomes positively charged and electrons are gained by another
material which becomes negatively charged. Therefore, during charging by
rubbing the object acquires equal and opposite charge.

Charging by conduction: In this method uncharged object is charged by
touching it with a charged object. During this process the electrons will flow
from one object to another and both objects get similar charge.

Charging by induction: In this method the uncharged object is charged from
a distance without actual contact. Charged object is brought close to the
uncharged object. Opposite charged can be induced on the object.

Interactive Elements / Activities:
Hands-On Activity
(Rubbing Balloons): Rub a balloon on hair or wool and observe
attraction to small paper bits—demonstrates charging by friction.
Conduction Demo: Touch a charged comb to an electroscope to show
transfer of charge.
Induction Demonstration: Bring a charged rod near small metal objects
(without touching) to observe induced movement.
Think& Reflect: Guess which method is involved in
common events like a shock from a doorknob or sticking balloon.

Real-Life Application Examples:
Friction: Rubbing plastic scale on dry hair—scale attracts small paper
pieces (friction).
Conduction: Transferring static charge between metal spheres in science
labs.