Explanation: Te=1/2is2dLs/dθr+1/2ir2dLr/dθr+isirdMsr/dθr. 5.In a doubly excited magnetic systems, the magnetic torques and forces act in such a direction as to tend to
A. decrease the field energy at constant currents
B. decrease the field co-energy at constant currents
C. increase the field energy at constant currents
D. none of the mentioned
Answer:A
Explanation: Te=1/2is2dLs/dθr+1/2ir2dLr/dθr+isirdMsr/dθr. 5.In a doubly excited magnetic systems, the magnetic torques and forces act in such a direction as to tend to
A. decrease the field energy at constant currents B. decrease the field co-energy at constant currents C. increase the field energy at constant currents D. none of the mentioned
Explanation: Te= ∂Wfld(is,ir,θr)/∂θr = ∂Wfld1(is,ir,θr)/∂θr