Answer to Question 1

 

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A search coil has 2500 turns and an area of 1.5 10-4 m2. It is placed between the poles of a large horseshoe magnet.  It is rapidly pulled out of the field in a time of 0.30 s.  A data-logger records an average value for the e.m.f of 0.75 V.  What is the flux density between the poles of the magnet?

 Change in flux = (0.75 V 0.30 s) 2500  = 9 10-5 Wb

 

B = F/A = 9 10-5 Wb 1.5 10-4  m2

 

B = 0.60 T