Please show steps One possible concern with MRI (magnetic resonance imaging) is
ID: 1452803 • Letter: P
Question
Please show steps
One possible concern with MRI (magnetic resonance imaging) is turning the magnetic field on or off too quickly. Bodily fluids are conductors, and a changing magnetic field could cause electric currents to flow through the patient. Suppose a typical patient has a maximum cross-section area of 6.6 times 10^-2 m^2. What is the smallest time interval in which a 5.7 T magnetic field can be turned on or off if the induced emf around the patient's body must be kept to less than 0.11 V ? Express your answer using two significant figures.Explanation / Answer
EMF = -N*d(phi)/dt
N = 1
phi = B*A
EMF = -A*dB/dt
EMF = 0.11 V
A = 6.6*10^-2 m^2
dB = 0 - 5.7 = -5.7
dt = A*dB/EMF = 6.6*10^-2*5.7/0.11
dt = 3.42 sec