An MRI technician moves his hand from a region of very low magnetic field streng
ID: 1869329 • Letter: A
Question
An MRI technician moves his hand from a region of very low magnetic field strength into an MRI scanner's 1.80 T field with his fingers pointing in the direction of the field. Find the average emf induced in his wedding ring, given its diameter is 1.90 cm and assuming it takes 0.230 s to move it into the field. 2.22 mV You are Your r eipt no. is 163-9303 Previoustnes s dissipated by the ring assuming that the resistance of the ring is 1.40 m2 (Discuss whether this current would significantly change the temperature of the ring.) Answer Tries 0/20Explanation / Answer
Here ,
for the induced emf
induced emf = change in flux/time taken
induced emf = 1.8 * pi * (0.019/2)^2/(0.230)
induced emf = 0.00222 V = 2.22 mV
Now , for the energy
energy = V^2/R * t
energy = 0.0022^2/0.0014 * 0.23
energy = 7.95 *10^-4 J
energy = 0.795 mJ
the energy dissipated is 0.795 mJ