# Problem: (a) An MRI technician moves his hand from a region of very low magnetic field strength into an MRI scanner’s 2.00 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 2.20 cm and assuming it takes 0.250 s to move it into the field. (b) Discuss whether this current would significantly change the temperature of the ring.

###### FREE Expert Solution

Induced emf is given by:

$\overline{){\mathbf{\epsilon }}{\mathbf{=}}{\mathbf{N}}\frac{\mathbf{d}\mathbf{\varphi }}{\mathbf{d}\mathbf{t}}}$

N = 1

dΦ = ΔB•A

ΔB = (B2 - B1) = 2.0 - 0.00 = 20 T

A = πr2 = π(d/2)2 = π(2.20cm/2)2(1m/100cm)2 = 1.21π × 10-4 m2

###### Problem Details

(a) An MRI technician moves his hand from a region of very low magnetic field strength into an MRI scanner’s 2.00 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 2.20 cm and assuming it takes 0.250 s to move it into the field.

(b) Discuss whether this current would significantly change the temperature of the ring.