An electron is at rest. Can this electron be set into motion by applying
a) a magnetic field?
b) an electric field?
Explain your answers.
I know that that one of the fields can only be caused by movement, but I don't remember which one...
I think I've figured it out. :)
To answer your question, let's go through the concepts of magnetic and electric fields and how they interact with an electron.
a) Magnetic Field: Yes, an electron can be set into motion by applying a magnetic field. This is due to the magnetic force acting on a charged particle like an electron. According to the Lorentz force equation, the force on a charged particle moving in a magnetic field is given by the equation F = qvBsinθ, where F is the force, q is the charge of the particle, v is the velocity of the particle, B is the magnetic field, and θ is the angle between the velocity and the magnetic field. When the electron is at rest (v = 0), the force acting on it due to the magnetic field is also zero. However, if the electron is initially at rest and an external magnetic field is applied perpendicular to its velocity, it will experience a force perpendicular to both the magnetic field and its velocity. This force will cause the electron to be set into motion.
b) Electric Field: No, an electron at rest cannot be set into motion by applying an electric field. Electric fields exert forces on charged particles, but for an electron at rest (v = 0), there is no velocity component to interact with the electric field. In order to move an electron using an electric field, it needs to have an initial velocity or be subjected to some external force in addition to the electric field.
In summary, an electron can be set into motion by applying a magnetic field, but not by applying an electric field when it is initially at rest.