Question

In this simulation, you can examine the magnetic field created by the current in a solenoid, which is a cylindrical coil of wire. Instead of using a spiral-shaped coil, the simulation approximates the coil with a stack of seven single loops. The plane of each loop is parallel to the x-z plane, with a radius of either 60 cm or 25 cm, and the displayed field is in the x-y plane.

The parallel-plate capacitor is the standard way to create a uniform electric field, while a current-carrying solenoid is a great way to create a uniform magnetic field, although the electric field is only perfectly uniform in the ideal case when the plates are infinitely large and the magnetic field is only perfectly uniform in the ideal case when the solenoid is made from closely packed loops that extend to infinity in the direction parallel to the axis of the solenoid.

(a) Which of the following statements correctly compare the ideal parallel-plate capacitor to the ideal solenoid? Select all that apply.

In the ideal capacitor changing the distance between the plates does not affect the electric field. In the ideal solenoid changing the radius of the solenoid does not affect the magnetic field.

In both ideal devices the fields are uniform inside the devices and zero outside.

A charged particle launched into the uniform field between the plates of the parallel-plate capacitor will follow a parabolic path. The same is true for a charged particle launched into the uniform magnetic field inside the solenoid.

Doubling the magnitude of the charge on each plate of the ideal capacitor doubles the electric field. Doubling the current in each loop of the solenoid doubles the magnetic field.

The electric field in the capacitor is produced by static charges, while the magnetic field in the solenoid is produced by moving charges.

The direction of the uniform electric field in the capacitor is parallel to the plates making up the capacitor, while the direction of the uniform magnetic field is parallel to the axis of the solenoid. b) Which of the following statements correctly describe what happens with the non-ideal solenoid shown in the simulation? Select all that apply. Increasing the size of the loops making up the solenoid increases the magnitude of the magnetic field at the center of the solenoid. Staying inside the solenoid, the magnetic field generally decreases in magnitude as you move away from the exact center of the solenoid along a direction perpendicular to the axis of the solenoid (moving along the x-axis would be such a direction, for instance). Reversing the direction of the current without changing its magnitude results in the magnetic field reversing at every point, but no change in the magnitude of the field at any point. Increasing the separation between the coils of the solenoid increases the magnitude of the magnetic field at the center of the solenoid. As long as the current is non-zero, changing the magnitude of the current without changing its sign results in a change in the magnitude of the magnetic field at every point, but no change in the direction of the field at any point. (Exceptions to this are points where the field is zero, which remain at zero.) The magnetic field generally decreases in magnitude as you move away from the exact center of the solenoid along the solenoid's axis (the y-axis, in this case).

Answer 1