Two long straight parallel wires carry equal currents that are in the same direction. What is the direction of the net magnetic field at point P midway between the two wires, or is the field at P zero?
field is zero
into the page
out of the page
none of these answers
In the figure, a small object with positive charge q is moving in a uniform magnetic field that is directed into the page. At the instant when the velocity of the object is toward the bottom of the page, what is the direction of the force exerted on it by the magnetic field, or is this force zero?
force is zero
into the page
out of the page
to the left
to the right
toward the top of the page
toward the bottom of the page