The field around a charged object, how to draw it, why it gets weaker with distance, and how fields explain sparks and attraction.
What you will learn
- Draw the field pattern around a charged sphere
- Say how the field strength changes with distance
- Explain non-contact forces between charges using fields
- Explain sparking using the idea of a strong field
The field around a charge
Every charged object has an electric field around it: the region where another charged object feels a force.
Field lines show the field. The arrows give the direction of the force on a small positive charge.
Around an isolated charged sphere the lines are straight and radial: outwards from a positive sphere, inwards to a negative one.
The rest of this lesson and its 9 practice questions are locked.
In this lesson
- The field around a charge
- Weaker further away
- Fields explain forces and sparks
- Try it: Explore the field around a charge
- Try it: Which way do the lines point?
9 practice questions, marked as you go; about 20 minutes in all.
Key terms
Electric field, Positive, Ionises
In this unit: Mains electricity, the National Grid and static
Direct and alternating current, the three-core cable and plug, electrical power and energy, the cost of electricity, the National Grid and transformers, and static charge and electric fields.