The strength of the electric field is indicated by how close the field lines are to each other. The closer the field lines, the stronger the electric field in that region.
Card 6: Effect of Electric Field 1 - Ping Pong Ball in an Electric Field
Ping Pong Ball in an Electric Filed
The ball will still remain stationary. This is because the force exert on the ball by the positive plate is equal to the force exerted on it by the negative plate.
If the ping pong ball is displaced to the right to touch the positive plate, it will then be charged with positive charge and will be pushed towards the negative plate.
When the ping pong ball touches the negative plate, it will be charged with negative charge and will be pushed towards the positive plate. This process repeats again and again, causes the ping pong ball oscillates to and fro continuously between the two plates.
Card 7: Effect of Electric Field 2 - Candle in an Electric Field
Candle in an Electric Field
The heat of the candle flame removes electrons from the air molecules around it, and therefore ionised the molecule.
If the candle is placed in between 2 plates connected to a Extra High Tension (E.H.T.) power supply, the positive ions will be attracted to the negative plate while the negative ions will be attracted to the positive plate.