The relationship between light and magnetic fields I have two questions.


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*Does light have a magnetic field?

*If not, can it be affected by other magnetic fields?

 A: Light is an electromagnetic wave. To be precise light is an oscillating electric and magnetic field.
Secondly, no light is not affected by other magnetic fields by external sources in vacuum. This is primarily due Principle of Superposition which states that fields themselves don't interact with each other. (In classical theory). But remember, light can affect the behaviour of electron. As the light wave is an oscillating field, hence the electron moves to and fro and there is no net motion, but if you could observe an electron as light propagates you'd see it moving/oscillating to and fro, but still it's net position wouldn't change.
But if the situation is not in vacuum then light waves passing by matter are affected by matter: slowed down, bent, absorbed, maybe even distorted into other frequencies of wave. 
Electric and magnetic fields can modify these interaction parameters of a substance, depending a lot on which substance it is.
A: Yes, light is a wavelike magnetic (and electric) field, so:

It practically doesn't interact with other magnetic fields.
In extreme circumstances (for example, around magnetars) some interaction is possible.
They can also "interact" through the mediation of matter.
