Answers:
- A magnetic force is exerted on an electric charge moving through a uniform magnetic field.
- The direction of the magnetic force acting on a moving electric charge in a magnetic field is perpendicular to the direction of motion.
- The direction of the magnetic force acting on a moving charge in a magnetic field is perpendicular to the direction of the magnetic field.
- An electric charge moving perpendicular to a magnetic field experiences a magnetic force.
Explanation:
The magnetic force exerted by a magnetic field on an electric charge is given by:
[tex]F=qvBsin \theta[/tex]
where
q is the charge
v is the velocity of the particle
B is the magnetic field
[tex]\theta[/tex] is the angle between the direction of v and B
From the formula, we notice the following:
- The magnetic force is zero when the electric charge is moving parallel to the field (because in that case, [tex]\theta=0, sin \theta=0[/tex])
- The magnetic force is zero when the electric charge is stationary (because v=0)
As a consequence, only the following choices can be correct:
- A magnetic force is exerted on an electric charge moving through a uniform magnetic field.
- The direction of the magnetic force acting on a moving electric charge in a magnetic field is perpendicular to the direction of motion.
- The direction of the magnetic force acting on a moving charge in a magnetic field is perpendicular to the direction of the magnetic field.
- An electric charge moving perpendicular to a magnetic field experiences a magnetic force.
