electric charges IGCSE

Electric Charge

IGCSE Combined Science (Physics)

Learning Objectives 1

• State that there are positive and negative charges

• State that unlike charges attract and that like charges repel

• Describe an electric field as a region in which an electric charge experiences a force

Electric Charge

• Objects can be Positive charge or Negative charge

• Opposite charges attract

• Like charges repel

Electric Field

The region in which an electric charged particle experiences an electric force.

Electric field of charged particles

The lines of force are directed outwards for a positive charge and inwards for a negative charge.

The electric line of force will never cross each other.

The closer the field lines, the stronger the electric field in that region

Multiple Choice

Electric charges that are alike _______ each other.

• Attract

• Repel

Multiple Choice

Electric charges that are different _______ each other.

• Attract

• Repel

Multiple Choice

The electric field lines for a positive charge is always directed away from the charge. True or False?

• True

• False

Multiple Choice

The electrical force between charges is strongest when the charges are

• close together

• far apart

• the electric force is constant everywhere.

• there is no pattern

Multiple Choice

What does it mean when the electric field lines are close together?

• the field is positive

• the field is negative

• The field is strong

• the field is weak

Multiple Choice

Consider the electric field lines shown in the diagram below. From the diagram, it is apparent that object A is ____ and object B is ____.

• +,+
• +,-
• -,+
• -,-

Learning Objectives 2

• Describe and interpret simple experiments to show the production and detection of electrostatic charges by friction

• State that charging a body involves the addition or removal of electrons

The basics

Negative charge electrons can flow but positive charge protons can't.

Negative charges will flow in the conductor.

Negative charges can stay on the surface of the insulator.

Charging by friction

From the rubbing, electrons transferred from the plastic rod to the cloth. Plastic rod became positively charge due to loss of electrons and cloth became negative charge as it gains electrons from Plastic rod.

Multiple Choice

When a balloon is rubbed on clothes it acquires a charge by ___________

• Induction

• reduction

• friction

• concuction

Multiple Choice

What is the name of the particle that is being transferred during charging by friction?

• Proton

• Neutron

• Electron

• Positron

Multiple Choice

Mr Robinson rubbed two balloons with a piece of wool. What will happen when the balloons are brought near each other?

• The balloons will repel each other.

• The balloons will attract each other.

• The balloons will become positively (+) charged.

• The balloons will pop.

Multiple Choice

When a glass rod is rubbed with silk and the glass rod becomes positively charged, what happens to the electrons?

• they are removed from the rod
• they are added to the rod

Multiple Choice

Which type of charges do these balloons have?

• like charges

• opposite charges

Multiple Choice

A balloon has a negative charge. A glass rod has a positive charge. What will happen when the rod is brought near the balloon?

• the balloon will be attracted to the rod

• the balloon will remain in place

• the balloon will be repelled by the rod

• the balloon will spin in circles

Learning Objectives 3

• Distinguish between electrical conductors and insulators and give typical examples

Electrical Conductors and Insulators

Electrical insulator: Electron is bound firmly to the atom

Electrical conductor: Some electrons are free to move from atom to atom

Multiple Choice

Metals such as copper, iron, gold, and silver are ...

• conductors

• brittle

• insulators

• resistors

Multiple Choice

glass, rubber, silk, and plastic are all examples of

• Conductors

• Insulator

• Thermel conductivity

• Materials