When you rub a balloon on your head, electrons are moved from your hair to the surface of the balloon. The electrons will stick to the side of the balloon where it was rubbed and it becomes charged. Because of this charge, the balloon attracts the hair and makes them stand.
This happens because of something called electric charge. Electric charges are surrounded by electric fields, which is an area of space around electrically charged particles or objects which exert force on other charged particles within the field.
Electric charge
An electric charge can either be positively or negatively charged, and they can cause charged particles to attract or repel. If two objects are oppositely charged, they will attract, and if the objects are similarly charged, they will move away from each other.
The reason why electric charges can cause objects to attract or repel each other is because they exert forces on each other. Coulomb’s Law states that the electric force between two charged objects is directly proportional to the product of the quantity of charge on the objects and inversely proportionate to the square of the separation distance between the two objects.
Electric field
An electric field is defined as a region of space around an electrically charged particle where an electric force can act. Electric fields are a quantity of vectors which can be visualised using an arrow that go towards or away from the charges. If the charge is positive, the lines should point radially outward. If the charge is negative, the lines should point radially inward.
Uniform electric field
When the electric field strength is the same at each point, it is defined as a uniform electric field. A perfect uniform electric field is not attainable in nature, but by putting two conductor plates parallel to each other, we can create a near-uniform field. The field strength does not change with distance and the potential difference between the points stays the same. Field lines are parallel to each other at equal distances.
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Non-uniform electric field
When the electric field is not constant at each point, it is called a non-uniform electric field. In a non-uniform electric field, two different points would have different magnitudes and directions.
Image credit: https://circuitglobe.com/wp-content/uploads/2017/01/non-uniform-electric-field.jpg
Electric potential energy
Electric potential energy is a scalar quantity, meaning it has only magnitude and no direction. It is the energy that is needed to move a charge against an electric field. More energy is needed to move a charge further in the electric field, and even more energy to move it through a stronger electric field. When a positive charge is brought near a positive point charge, the work done will be converted into electric potential energy and is stored in the charge. However, when a negative charge is taken away from the positive charge, the negative charge gains electric potential energy.
Conclusion
There is much to learn about electric fields. But there is nothing to worry about if you are attending physics tuition as they will cover all the principles and theories you will need to know. Sign up for O level physics tuition class today and enhance your learning experience!
