Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

12. /1 points SerCP11 20.P011 My Notes Ask Your Teacher Inductive charging is us

ID: 2036874 • Letter: 1

Question

12. /1 points SerCP11 20.P011 My Notes Ask Your Teacher Inductive charging is used to wirelessly charge electronic devices ranging from toothbrushes to cell phones. Suppose the base unit of an inductive charger produces a 1.30 × 10-3 T magnetic field. Varying this magnetic field magnitude changes the flux through a 16.0-turn circular loop in the device, creating an emf that charges its battery. Suppose the loop area is 2.75 x 104 m2 and the induced emf has an average magnitude of 5.50 V. Calculate the time required (in s) for the magnetic field to decrease to zero from its maximum value.

Explanation / Answer

lnduced emf is given by,

e = -N*A*dB / dt

e = -N*A*(0 - B) / t

Put the values,

5.5 = -16 * 2.75*10^(-4) * (0 - 1.3*10^(-3)) / t

t = 10.4*10^(-7) s