New
New
Year 10
OCR
Higher

Electric fields

I can describe the properties of electric fields.

New
New
Year 10
OCR
Higher

Electric fields

I can describe the properties of electric fields.

Lesson details

Key learning points

  1. Two unlike electric charges attract each other.
  2. Two like electric charges repel each other.
  3. There is an electric field radiating out from an electric charge.
  4. Electric field lines show the direction of force on a positive electric charge.
  5. The closer electric field lines are to each other, the stronger the electric field.

Common misconception

Pupils think that electric field lines show the movement of moving charges, rather than the force acting on them.

Add force arrows to electric field diagrams to show the size of the force they represent at different points.

Keywords

  • Positive electric charge - The type of charge produced when electrons are removed.

  • Negative electric charge - The type of charge produced when electrons are gained.

  • Electrostatic force - The type of force due to electrically charged objects.

  • Van der Graaff - A device that produces electric charge and is used in electrostatic experiments.

  • Electric field - The invisible field around a charged object that causes another charged object to experience a force.

A stack of small pie tins placed on the top of a Van der Graaff dramatically shows the direction of electric field lines (with the movement of pie tins also influenced by the gravitational force).
Teacher tip

Equipment

For demonstration: Van der Graaff generator, polystyrene balls, empty pie tins, polythene rods, watch glass, duster and balloons.

Content guidance

  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Which of the following are types of electric charge?
Correct answer: positive
Correct answer: negative
north-seeking
south-seeking
Q2.
When two objects at a distance experience forces that pull them towards each other, we say they attract. When two objects at a distance experience forces that push them apart, we say they .
Correct Answer: repel
Q3.
In the diagram, which of the labelled distances is the radius of the black circle?
An image in a quiz
Correct answer: A
B
C
Q4.
A material that does not allow current to flow through it is called an electrical insulator. A material that allows current to flow through it is called an electrical .
Correct Answer: conductor
Q5.
When one object rubs against another, the two objects exert forces on each other. What is the name of this type of force?
drag
Correct answer: friction
upthrust
resistance
normal contact force
Q6.
There is a magnetic field around a magnet. Which of the following statements about magnetic fields are correct?
Correct answer: We cannot see them.
They cause forces on positively and negatively charged objects.
Correct answer: They cause forces on north-seeking and south-seeking poles.

6 Questions

Q1.
The force between charged objects is called the force.
Correct Answer: electrostatic
Q2.
A balloon is rubbed against a wall. After this, it sticks to the wall. Which of the following statements explain why the balloon sticks to the wall?
Correct answer: The balloon and wall have equal and opposite charges.
The balloon and wall have equal charges of the same type.
Atoms have transferred between the balloon and the wall.
Nuclei have transferred between the balloon and the wall.
Correct answer: Electrons have transferred between the balloon and the wall.
Q3.
The arrows on electric field lines point in the direction of the force on…
any charge.
Correct answer: a positive charge.
a negative charge.
a north-seeking pole.
a south-seeking pole.
Q4.
How does an electric field diagram show areas where the field is stronger?
Correct answer: The field lines are closer together.
The field lines are farther apart.
The field lines are thicker.
The field lines are thinner.
The diagram does not show this.
Q5.
The picture shows five small positive charges in the field of a large positive charge. Which small charge has an arrow that correctly points in the direction of the force due to the large charge?
An image in a quiz
A
B
Correct answer: C
D
E
Q6.
A small metal pie tin is placed on top of a Van der Graaff generator’s dome and the generator is switched on. After a short time, the pie tin moves up. Which of the following statements explains why?
Correct answer: The pie tin gains the same type of charge as the dome.
The pie tin gains the opposite type of charge to the dome.
The electrostatic force on the tin becomes less than its weight.
Correct answer: The electrostatic force on the tin becomes greater than its weight.