A thick metal slab carries a current I as shown. A uniform magnetic field B points perpendicular to the slab (and into the page). If point P on the slab is at a higher potential than point Q , what can we say about the charge carriers that produce the current in the slab?
a.They are positive.
b.They are negative.
c.They could be either positive or negative, but we can't tell without more information.
d.The situation is impossible: point could never be at a higher potential than point , no matter what the sign of the charge carrier
( P is upper side and Q is lower side)
I think upside( at p) electrons are more because of higher potential, so they are negative. But I am not sure. pls help me
Usually one would assume a metal slab is a conductor and there is no potential difference between top and bottom. I would be inclined to say d but do not have the picture entirely.
has anyone checked if A was the right answer?
To determine the charge carriers that produce the current in the slab, we can use the principle of electric potential. If point P on the slab is at a higher potential than point Q, it means that positive charges have a tendency to move from P to Q in the presence of an electric field.
In this scenario, the magnetic field is perpendicular to the slab, which affects the motion of the charge carriers (electrons or positive charges). The Lorentz force acting on the charge carriers due to the magnetic field causes them to experience a force perpendicular to both the current direction and the magnetic field direction. By applying the right-hand rule, we can determine that electrons (negative charge carriers) will experience an upward force.
Since the net force on the carriers is upward, the negative charges (electrons) will accumulate at the top surface of the slab (point P), while positive charges (holes or other charge carriers) will accumulate at the bottom surface (point Q). Therefore, the correct option is b. The charge carriers that produce the current in the slab are negative (electrons).
In summary, the combination of the magnetic field and the potential difference between points P and Q causes the flow of negative charge carriers (electrons) from P to Q, resulting in an electric current.