A cross-section of a circular wire loop carrying an unknown current is shown above. The arrows represent the direction of the magnetic field. The color of the arrows represents the magnitude of the field with magnitude increasing as the color changes from blue to green to red to black. You can click-drag the center of the loop to reposition it and you can click drag the top or bottom of the loop to change its size. The wire cross-sections are color coded. Does current flow out of the red end or the blue end? Start
Note: You may double click anywhere inside the animation to superimpose a magnetic field line on the direction field.
A cross section of three wires carrying unknown currents is shown above. How many wires are carrying current out of the plane of the simulation, that is, out of the computer monitor? You can double-click anywhere inside the animation to draw a magnetic field line. You can also click-drag the wires but this will erase any field line that you have drawn. Start
A wire carrying an unknown current is shown above. An external magnetic field that has constant magnitude and direction is applied to the top half of the simulation. In addition, there is the magnetic field produced by the current in the wire. The direction arrows show the vector sum of these two fields. (The color of the direction arrows represents the magnitude of the field as before.) Find the current in the wire by click-dragging the wire into the external field if the external field has a magnitude of 2 Tesla. Observe the force vector and the force/length in the yellow message box in the lower left hand corner. Start
An unknown charged particle is fired into an apparatus with a controllable magnetic field. The animation shows a top view of the apparatus. The magnetic field points into or out-of the plane of the view depending on the sign of Bz. That is, the z axis is directed out of the computer monitor. Enter a field value with magnitude less than 5
Bz=
and press the play button whenever you wish to change the field. Observe the force vector on the particle. Determine the charge to mass ratio of the particle by studying the dynamics. Time is measured in seconds and distance in cm. Start
A wire carrying an unknown current is shown above. Determine the current by click-dragging inside the animation to measure the magnetic field. Assume that the distance shown is in cm and B is shown in milli Tesla. Start
Interactive Help
Five wires are carrying unknown currents into or out of the plane of the simulation as shown above. The arrows are proportional to the forces on the wires. How many wires are carrying current in the same direction as the red wire? You can click-drag on any wire to change its position. Start
How many loops are necessary to create a solenoid with a uniform magnetic field? Build a solenoid by adding current loops to the simulation and then determine the current flowing inside a loop by measuring the magnetic field inside the solenoid. You can measure the magnetic field by click-dragging the mouse and observing the yellow message box. The field is measured in micro Tesla, mT, and distance is measured in meters. You can also superimpose field lines by double-clicking inside the animation.
An unknown charged particle is fired into a velocity selector with controllable electric and magnetic fields. The animation shows a top view of the apparatus. The magnetic field points into or out of the view depending on the sign and the electric field is up or down depending on the sign. Enter E and B field values
Ey=
and press the play button every time you wish to change the field. Observe the force vector on the particle. The value of Ey is constrained to -10 < Ey < 10 and the value of Bz is constrained to -5 < Bz < 5. Start
