"An electron always experiences a force in an electric field, but not always in a magnetic field

step 1 Hello and welcome to this video solution of numerate. So here we are given that the assertion wh

"An electron always experiences a force in an electric...

Key Concepts

Electric Field

An electric field is a region of space where a charged particle experiences a force, described by F = qE. This force acts on the charge regardless of its state of motion, meaning that an electron will always be affected by an electric field due to its intrinsic charge.

Magnetic Field

A magnetic field exerts a force on a moving charged particle described by the cross product F = q(v × B). This means that if the electron is either at rest or moving in a direction parallel to the magnetic field, the magnetic force will be zero, demonstrating that an electron does not always experience a force in a magnetic field.

Lorentz Force

The Lorentz force is the total force experienced by a charged particle in the presence of both electric and magnetic fields, given by F = q(E + v × B). This equation highlights the fact that while the electric component acts regardless of the particle's motion, the magnetic component depends on the velocity of the particle, reinforcing the statement in the question.

Velocity Dependence

The dependency of the magnetic force on the velocity of the electron is a crucial concept. Unlike the electric force, which is always exerted as long as the charged particle is present in the field, the magnetic force only acts when there is a component of the electron’s velocity perpendicular to the magnetic field, explaining why sometimes no force is observed in a magnetic field.

Transcript

Please give Ace some feedback