標題:
此文章來自奇摩知識+如有不便請留言告知
An E.M question
發問:
Explin it clearly. 1. A square wire frame of length of side 15.7 cm is placed in a uniform magnetic field of 0.6T into the paper. Its shape is then changed into a circle in 0.5s. Find the average induced e.m.f and the diection of the induced current in the frame in this period.
最佳解答:
Take π = 3.14, then Original area = 15.7 x 15.7 = 246.49 cm2 = 2.4649 x 10-2 m2 Radius of circle = 15.7 x 4/(2π) = 10 cm Hence new area = 102 x π = 314 cm2 = 3.14 x 10-2 m2 Thus change in flux linkage = (3.14 - 2.4649) x 10-2 x 0.6 = 0.40506 Wb Hence it is an increase in flux linkage and by the Lenz's law, the induced current flows anti-clockwisely when viewing from the top of the coil. with induced e.m.f. (average) = 0.40506/0.5 = 0.81012 V
其他解答:
留言列表
