BDL. Shown are 3 integration paths shaped like letters B, D, and L with enclosed identical currents with directions shown. What is the correct order of their line integral ?

Concentrix. Consider two concentric circular loops of radius and , respectively, lying in the -plane. Each loop carries a current moving in the directions shown. What is the magnitude of the net magnetic field at point at distance from the center of the loops?

Pawawell. Two straight, parallel wires carry currents in opposite directions. One wire has a current of 5.0 [A] while the other has 6.0 [A]. If the wires are spaced 4.0 [cm] apart, what is the force exerted by the wires on each other per unit length and what is their interaction?

Two lanes. Consider two current-carrying wires shown in the figure. The top wire at is carrying a current to the right and contains a charge element of width at . The bottom wire at is carrying a current to the left and contains a charge element of width at . What is the net magnetic field at due to these charge elements?

Singkil. Consider four long, straight, parallel wires arranged in the corners of a 20.0 [cm] square and are carrying currents directed as shown in the figure. The into the page currents are 5.0 [A], while the out of the page currents are 2.5 [A]. What is the magnitude and direction of at point , the center of the square?

Scattering charges. The figure shows a system of three electrons moving at velocities and a proton moving at velocity as shown. All charges are in the plane of the page (xy-plane). What is the magnitude and direction of the net magnetic field at point ?

Stability Check. Consider a circular loop shown which carry current in the direction indicated. If the loop is in a uniform magnetic field in the -direction, which of the following statements is/are TRUE about the loop?

I. The loop is in stable equilibrium.

II. The loop is in unstable equilibrium.

III. The loop experiences no torque.

Loop-in. A loop carries a current as shown and is immersed in a uniform magnetic field . What is the direction of the torque on the loop?

Cross product check. A wire with a current along the -direction is under the influence of a uniform magnetic field along the -direction. Along what direction does the magnetic force on the wire segment point? 

B-I-N-I-verse. A wire, bent as shown, is immersed in a uniform magnetic field 2.50 [T] directed to the right. The vertical segments are 1 [m] long while the diagonal segment is [m]. Current 4.00 [A] flows in the direction shown. What is the net force on the wire?