20.1 A2 Level

Concept of a magnetic field

6 flashcards to master this topic

Definition Flip

Define a magnetic field.

Answer Flip

A magnetic field is a region of space where a moving charge or magnetic material experiences a force. It is a vector field, possessing both magnitude and direction.

Definition Flip

What are the two sources that produce magnetic fields?

Answer Flip

Magnetic fields are produced either by moving electric charges (electric current) or by permanent magnets due to the intrinsic magnetic dipole moment of elementary particles such as electrons.

Key Concept Flip

Describe how magnetic field lines are used to represent a magnetic field.

Answer Flip

Magnetic field lines indicate the direction of the force that a north magnetic pole would experience. The density of the lines indicates the strength of the field; closer lines mean a stronger field.

Key Concept Flip

What determines the direction of a magnetic field line?

Answer Flip

The direction of a magnetic field line at any point is the direction of the force on a 'north' magnetic pole at that point. The field lines always point from the north pole to the south pole outside the magnet.

Key Concept Flip

How does the strength of the magnetic field relate to the spacing of magnetic field lines?

Answer Flip

The closer the magnetic field lines are to each other, the stronger the magnetic field is in that region. Conversely, widely spaced lines indicate a weaker field.

Definition Flip

Why is a magnetic field considered a 'field of force'?

Answer Flip

A magnetic field is a region where a force is exerted on specific objects. In this case, the specific objects are moving electric charges and magnetic dipoles.

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