A rectangular loop of wire with sides 0.129 and 0.402 m lies in a plane perpendicular to a constant magnetic field (see part a of the drawing). The magnetic field has a magnitude of 0.888 T and is directed parallel to the normal of the loop's surface. In a time of 0.172 s, one-half of the loop is then folded back onto the other half, as indicated in part b of the drawing. Determine the magnitude of the average emf induced in the loop.

Sally turns on her cellular telephone to speak to her friend who is located thousands of miles away. which of the following best describes how such a telephone is able to transmit and receive information? a. the cellular telephone transmits, receives, and encodes information using only sound waves. b. the cellular telephone transmits, receives, and encodes information using only electromagnetic waves. c. the cellular telephone transmits information by electromagnetic waves to a receiver which then encodes them and produces sound. d. the cellular telephone transmits information by sound waves to a receiver which then encodes them and produces electromagnetic waves.