In Physics fields describe regions of space that contain some sort of value.
Thus objects placed in that field, may have some sort of behaviour due to the presence of that field.
Many fields will exert a force on an object placed in that field
Take for example, a gravitational field. A mass, when placed in that field, will experience a force whose value is dependent on the nature of that field. In this case, there will not only be magnitude of the force, but also a direction to which that force acts, which is towards the main mass that generates that gravitational field.
Therefore fields are often represented as arrows, to show the direction of the force.
This brings us to electric fields. Charges generates fields that cause other charges to experience a force in that field.
Interactive
Before we look at the theory, Let's look at an interactive.
Thus objects placed in that field, may have some sort of behaviour due to the presence of that field.
Many fields will exert a force on an object placed in that field
Take for example, a gravitational field. A mass, when placed in that field, will experience a force whose value is dependent on the nature of that field. In this case, there will not only be magnitude of the force, but also a direction to which that force acts, which is towards the main mass that generates that gravitational field.
Therefore fields are often represented as arrows, to show the direction of the force.
This brings us to electric fields. Charges generates fields that cause other charges to experience a force in that field.
Interactive
Before we look at the theory, Let's look at an interactive.
- Place a positive charge in the region below. You can alter the strength of the charge be increasing the number of point charges
What do you notice abut the strength and direction of the field? - The arrow represent the force a positive test charge will experience in that field
- Add a sensor. It represents a positive test charge. Move it around
What does the arrow generated represent? - Reset the screen and repeat using a negative charge
What do you notice?
Theory
Lets now look at the theory. The video examines the nature of electric fields and how we represent fields around single charges, multiple charges and plates.
Interactive
Return to the pHET animation above and see if you recreate the various example mentioned in the video
Return to the pHET animation above and see if you recreate the various example mentioned in the video
A bit of fun
This fun activity requires you to score hockey goals using your understanding of electric fields.
Place either positive charges or negative charges around the screen to get the black test charge into the goal. Try to do it with the least number of charges.
Level one is easy, but three is a challenge!
This fun activity requires you to score hockey goals using your understanding of electric fields.
Place either positive charges or negative charges around the screen to get the black test charge into the goal. Try to do it with the least number of charges.
Level one is easy, but three is a challenge!
