As shown in the figure,a coil of wire is placed in the xy-plane,centered on the z-axis.A solenoid is centered on the z-axis and is carrying a steady dc current.Which one of the following actions will not result induce an emf in the coil?
A)Rotate the coil about the x-axis.
B)Rotate the coil about the y-axis.
C)Rotate the coil about the z-axis.
D)Move the coil toward point P.
E)Change the current in the solenoid.

Question

As shown in the figure,a coil of wire is placed in the xy-plane,centered on the z-axis.A solenoid is centered on the z-axis and is carrying a steady dc current.Which one of the following actions will not result induce an emf in the coil? 
A)Rotate the coil about the x-axis. 
B)Rotate the coil about the y-axis. 
C)Rotate the coil about the z-axis. 
D)Move the coil toward point P. 
E)Change the current in the solenoid.

Quizplus · Accepted Answer

If the coil is rotated about the z-axis, the coil will still pass through the same magnetic field lines, and therefore an emf will still be induced in the coil. However, if the coil is rotated about the x or y-axis, its orientation with respect to the magnetic field lines will change, resulting in a change in flux and therefore inducing an emf. Similarly, if the coil is moved toward point P, its orientation with respect to the magnetic field lines will change, inducing an emf. Lastly, changing the current in the solenoid will also induce an emf in the coil as it alters the strength of the magnetic field.

As Shown in the Figure,a Coil of Wire Is Placed