Suppose you have a long straight wire carrying current in th

Suppose you have a long straight wire carrying current in the +x direction and a long straight wire carrying an equal current in the +y direction. Then the magnetic field will be zero in the xy plane, along the lines (a) x=y (b)x=-y (c) nowhere. The magnetic force on a charged particle will be non-zero (a) if the particle is moving in the field direction (b) is moving at right angles to the field direction (c) is not moving at all. A particle sent into a magnetic field at right angles with respect to its direction (a) will experience a force perpendicular to its direction of motion and perpendicular to the field direction (b) will experience no force, (c) will

Solution

7) a (x=y)

8) b (moving at right angle to the field direction, F = q (v x B))

9) a (from equation, F = q (v x B))