Question

Magnetic resonance imaging (MRI) is a medical technique for producing pictures of the interior of the body. The patient is placed within a strong magnetic field. One safety concern is what would happen to the positively and negatively charged particles in the body fluids if an equipment failure caused the magnetic field to be shut off suddenly. An induced emf could cause these particles to flow, producing an electric current within the body. Suppose the largest surface of the body through which flux passes has an area of 0.034 m2 and a normal that is parallel to a magnetic field of 1.0 T. Determine the smallest time period during which the field can be allowed to vanish if the magnitude of the average induced emf is to be kept less than 0.010 V.

Answer 1

This problem is based on faraday's law as explained below...

Area of body ZAC = 0.34 m2. Magnitude of magnetic field & But = 1T. Maxth value of enfinduud = olv.. This emf the problem is based on faraday's law in which. gets induced due to change in flux through given area. This induced emp e is. 9 8 8 8 = - Aở A9 = te - 6. = BRA - Bi A. --Pity .034 = - 0034 weber when emf induced is mam, then time taken. for this emf is minimum as shown. Now lot) min = -4% e max - -2-6034 webers oo [ 18t) in = 3.48 So minimum time taken is 3.43.