Magnetic field

How it is used

Symbol B. Outside a magnet, field lines go from the north pole to the south pole. A charge moving through a magnetic field feels a force, and a changing field induces a current. The Earth's magnetic field at the surface is roughly 50 microteslas.

Example sentences

1. The wire is placed in a uniform magnetic field of 0.2 T.

2. Iron filings show the shape of the magnetic field around the bar magnet.

Common collocations

• uniform magnetic field
• magnetic field lines
• field strength
• Earth's magnetic field
• magnetic flux density

Related terms

• electric fieldThe region around a charged object where another charge feels an electric force. Its strength is the force per unit charge, measured in newtons per coulomb (N/C) or volts per metre (V/m).
• electromagnetic inductionThe production of a voltage, and often a current, in a conductor when the magnetic field through it changes. It is the principle behind generators and transformers.
• electric currentThe rate at which electric charge flows past a point in a circuit. It is measured in amperes (A), and one ampere is one coulomb of charge per second.
• electric chargeA basic property of matter that makes particles feel electric forces. Charge can be positive or negative; like charges repel and unlike charges attract. It is measured in coulombs (C).
• forceA push or a pull that can change how an object moves or change its shape. It has both size and direction and is measured in newtons (N).

More terms: Electricity and Magnetism

• voltage
• resistance
• Ohm's law
• circuit
• capacitor
• electromotive force