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

Rotating the coil about the z-axis will not result in an induced emf because the magnetic field produced by the solenoid is also centered on the z-axis, and therefore the flux through the coil will remain constant regardless of its rotation about the z-axis. In contrast, rotating the coil about the x-axis or the y-axis will change the amount of flux passing through the coil and induce an emf. Moving the coil toward point P will also change the amount of flux passing through the coil, and changing the current in the solenoid will change the magnetic field and therefore the flux passing through the coil, both resulting in an induced emf.

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