Which is true about moving charges? A) The direction of movement of the charge determines the direction of the magnetic field it produces B They always produce magnetic fields C They only produce magnetic fields when the material in which they move is heated D They are neutralized by magnetic fields

B They always produce magnetic fields

Explanation:

When a charge is moving, it produces an electric field owing to the fact that it is a charged particle. In addition to this, it also produces a magnetic field.

This is well captured in the basics of electrostatics and special relativity. The fact that a moving charge produces a magnetic force can also be proven mathematically.

Hence, among the options, it is true that a moving charge always produce magnetic fields

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.