A charged particle moves through a magnetic field. In which situation is the magnetic force zero?
When the particle moves in the direction of the magnetic field vector.
Which describes the vector calculation giving the magnetic force on a charged particle moving through a magnetic field?
It is the cross product of the velocity vector and the magnetic field vector, which gives a vector perpendicular to those vectors.
Which is true about a magnetic force acting on a charged particle moving through a magnetic field?
The force cannot change the speed.
A charged particle moves through uniform electric and magnetic fields. In which case is there the possibility that the electric force and magnetic force cancel?
The electric field and the magnetic field are perpendicular.
A charged particle moves through uniform electric and magnetic fields, and the electric force and the magnetic force happen to cancel. If we increase the particle's speed, which is true about the forces?
The magnetic force is then greater than the electric force.
When the current in a Hall effect experiment is first turned on, which describes the electric and magnetic fields?
The electric field across the strip width increases in magnitude and the magnetic field is constant in magnitude.
In a cyclotron, as the proton spirals outward, what happens to the frequency of circling?
remains the same
A wire with current lies in a uniform magnetic field. In which situation is the magnetic force on the wire zero?
When the length vector is in the direction of the magnetic field vector.
Which describes the torque on a magnetic dipole in a uniform magnetic field?
It tends to rotate the dipole so that the dipole moment vector is in the direction of the magnetic field.
A magnetic dipole is in a uniform magnetic field. For which orientation is the potential energy of the dipole least?
The dipole moment is in the direction of the magnetic field.
An electron is moving north in a region where the magnetic field is south. The magnetic force exerted on the electron is:
zero
A magnetic field exerts a force on a charged particle:
if the particle is moving across the field lines
An electron and a proton are both initially moving with the same speed and in the same direction at 90? to the same uniform magnetic field. They experience magnetic forces, which are initially:
equal in magnitude but opposite in direction
The magnetic force on a charged particle is in the direction of its velocity if:
never
A uniform magnetic field is in the positive z direction. A positively charged particle is moving in the positive x direction through the field. The net force on the particle can be made zero by applying an electric field in what direction?
Positive y