Question

The friends start by discussing what they know with respect to electric and magnetic fields. Alexa mentions several differences between the two fields. Which of her statements are correct? (Select all that apply.)
A. "The electric force vector is along the direction of the electric field, whereas the magnetic force vector is perpendicular to the magnetic field."
B. "The electric force acts on a charged particle regardless of whether the particle is moving, whereas the magnetic force acts on a charged particle only when the particle is in motion."
C. "The electric force does work in displacing a charged particle, whereas the magnetic force associated with a steady magnetic field does no work when a particle is displaced."
D. "The kinetic energy of a charged particle moving in an electric field is not altered, whereas the kinetic energy of a charged particle moving in a magnetic field is either increased or decreased, depending on the direction of motion."

Answer 1

Answer:

A. "The electric force vector is along the direction of the electric field, whereas the magnetic force vector is perpendicular to the magnetic field."

D. "The kinetic energy of a charged particle moving in an electric field is not altered, whereas the kinetic energy of a charged particle moving in a magnetic field is either increased or decreased, depending on the direction of motion."

Explanation:

Electric fields originate from voltage differences, the higher the voltage, the stronger the resulting field. Magnetic fields originate from electric currents, a stronger current results in a stronger field. An electric field exists even if there is no current. When there is current, the magnitude of the magnetic field will change with power consumption, but the strength of the electric field will remain the same.