Electromagnetic Field Theory: A Problem Solving Approach Part 51. Electromagnetic field theory is often the least popular course in the electrical engineering curriculum. Heavy reliance on vector and integral calculus can obscure physical phenomena so that the student becomes bogged down in the mathematics and loses sight of the applications. This book instills problem solving confidence by teaching through the use of a large number of worked problems. To keep the subject exciting, many of these problems are based on physical processes, devices, and models. This text is an introductory treatment on the junior level for a two-semester electrical engineering. | Problems 475 a What is the open circuit Hall voltage Hint The transverse current of each carrier must be zero. b What is the short circuit Hall current 17. A highly conducting hollow iron cylinder with permeability n and inner and outer radii R and Rz is concentric to an infinitely long de line current adapted from L. V. Bewley Flux Linkages and Electromagnetic Induction. Macmillan New York 1952 pp. 71-77 . b a What is the magnetic flux density everywhere Find the electromotive force EMF of the loop for each of the following cases. 476 Electromagnetic Induction b A highly conducting circuit abed is moving downward with constant velocity Vo making contact with the surfaces of the cylinders via sliding brushes. The circuit is completed from c to d via the iron cylinder. c Now the circuit remains stationary and the iron cylinder moves upwards at velocity Vo- id Now a thin axial slot is cut in the cylinder so that it can slip by the complete circuit abed which remains stationary as the cylinder moves upwards at speed Vo. The brushes are removed and a highly conducting wire completes the c-d path. 18. A very long permanently magnetized cylinder ML rotates on a shaft at constant angular speed w. The inner and outer surfaces at r a and r b are perfectly conducting so that brushes can make electrical contact. a If the cylinder is assumed very long compared to its radius what are the approximate values of B and H in the magnet b What is the open circuit voltage c If the magnet has an Ohmic conductivity a what is the equivalent circuit of this generator d What torque is required to turn the magnet if the terminals are short circuited 19. A single spoke wheel has a perfectly conducting cut rim. The spoke has Ohmic conductivity r and cross-sectional area A. The wheel rotates at constant angular speed o 0 in a sinusoidally varying magnetic field Bz Bo cos cat. a What is the open circuit voltage and short circuit current b What is the equivalent circuit Problems 477 0 B2 .
