Revision Topic 123

Two like charges

•  neutralize each other.
• repel each other. 
• must be neutrons. 
• attract each other.

What direction are the electric field lines around an electron?

• towards the charge
• away from the charge

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

What direction are the electric field lines around a proton?

• towards the charge

• away from the charge

When distance increases, electrostatic force ____________; we call this relationship ____________ proportional

• decreases;directly
• decreases;inversely
• increases;inversely
• increases;directly

Recap:

Coulomb’s law states that the force between two charged objects will __________ when the magnitude of the object’s charge increases.

Coulomb’s law also states that the force between two charged objects will __________ when the distance between objects increases.

• increase; increase

• increase; decrease

• decrease; increase

• decrease; decrease

Which two particles are attracted to each other?

• Two neutrons

• A proton and an electron

• Two protons

• An electron and a neutron

When the distance between two charges is halved, the electrical force between the charges

• quadruples

• reduces to one fourth

• halves

• doubles

list the properties of electric field lines

• they never cross each other

• they move from positive to the negative charges

• they can cross each other at strong fields

• they are parallel at uniform fields

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

• +,+
• +,-
• -,+
• -,-