Final answer:
A magnetic field can induce a current in a wire coil through electromagnetic induction, where movement or change in the magnetic field pushes electrons to create a current. The direction of the current is determined using the right-hand rule, and the effect is quantified by Faraday's law.
Step-by-step explanation:
A magnetic field can cause a current to flow in a wire coil through a process known as electromagnetic induction. When a wire coil moves through a magnetic field, or when the magnetic field around the coil changes, the magnetic field exerts a force on the electrons in the wire, pushing them and creating an electric current. If the wire is formed into a coil, the amount of induced current increases because each loop of the coil experiences the magnetic field.
Using the right-hand rule, one can determine the direction of the induced current. According to this rule, if you point your thumb in the direction of the wire's motion relative to the magnetic field, and your fingers in the direction of the magnetic field lines, the induced current flows in the direction your palm faces.
- Faraday's Law of Electromagnetic Induction
Faraday's law quantifies this effect by stating that the induced electromotive force (EMF) in any closed circuit is equal to the negative of the rate of change of the magnetic flux through the circuit. Thus, stronger magnetic fields or faster changes in the magnetic field can induce larger currents in the wire coil.