Electric Charges and Fields: Introduction

Electrostatics

• Electrostatics is the study of forces, fields, and potentials arising from static charges.

Discovery of Electrostatics

• Thales of Miletus is credited with the discovery that amber rubbed with wool or silk cloth attracts light objects.

Static Electricity

• The phenomenon of seeing a spark or hearing a crackle when taking off synthetic clothes or sweater is attributed to static electricity.
• In the context of electrostatics, the term 'static' refers to electricity at rest.

Electricity

• Electricity is named after the Greek word 'elektron', meaning amber.

Electric Discharge

• Lightning is another common example of electric discharge.

Like and Unlike Charges

• When two glass rods rubbed with wool or silk cloth are brought close to each other, they repel each other.
• The property that differentiates the two kinds of charges is that like charges repel each other, while unlike charges attract each other.

Benjamin Franklin

• American scientist Benjamin Franklin named the charges as positive and negative.

Electric Charge

• Electric charge is an entry that is a fundamental property of matter.

Charge Interaction

• Like charges repel each other, while unlike charges attract each other.
• When two charged bodies are brought in contact, the charges acquired after rubbing neutralize each other.

Detecting Charge

• An electroscope is a simple apparatus to detect charge on a body.

Charged Objects

• An object possessing an electric charge is called a charged object.
• An object with no charge is called a neutral object.
• The charges on a glass rod or cat's fur are called static charges.