解设左边直导线﹑圆弧、右边直导线在[tex=0.643x1.286]inoCUnU4RYMHbxo7c4/mgQ==[/tex]点处产生的磁感应强度分别为[tex=2.5x1.214]68xlrbw/KLkMynZWtq/aj7DQ9gS+WPdpbqNjS05qrYI=[/tex]、[tex=1.429x1.214]ooLBikw+whKxts4+lPEw7A==[/tex],则[tex=19.643x6.214]ifE9NWj3X6IpRVSt3T5ITs0RikygGnhbN8I9vJrPEmDVTwuzpG+TG1cfcG/hf7JRZlUNnjETrnaRPWy5mDEdv98d3fz/jBTYR/MEth6KWpVBqTk7FYlMoPBoIZkLTnfiX0fI1zuMdJR0qQm4/xJmV7KkW1oD4d65eEcqE2SYlybNVO+G+mV4EwWjqRc7tS+TDRVMnaBCtptDAhkIJNkI9oi2xvAQI7G4zb1yDAs+9nu/ByeaZKxqxwYWNmxO7fDtr83Wgcc94RmdZifZfZwbbLm1AZ4LYD79/B+lYqm70m0xWHuUeAAj91k8BsiB6wko05eqoac+BOKwDoLEJ/kPWjflClMv+YGmFGLVYuLJxQI=[/tex][tex=15.857x4.214]XL4MAbJGFxjQ4RySRoDlDqgpd6Q4V4EVuMVuEBS+aJlLr2P+6MY32d+yVd2hJ3dAUklBCvU4w/eupnJlCZbbZkGzmmhKs5ADeUCoUag2OHJJus5Ad/7gSWAAV9FgBUYBYjziqkVYv5NUxrTHHAqZppKxEYHAz+UnVStHNQuCWyDun32X3W+xtioKT73njRaSGkLIuOqFDkAknJdPvy25CoLKf9lKuhkxN5geYdz42gw=[/tex]因为[tex=3.929x1.214]Ce95BmbxV8+IVRDsY4blJSsktjHBZday1ayqiPsDoTI=[/tex]方向相同,所以[tex=21.143x3.357]VJiv34WqG2BZBMf/DuUmHlFPLVm7zUeSfq5rYYvC2pci0SQ/IHW9i4iE24zmsBEssqFGxvERUwcNnYpwGfH3AepfDN+homxyA50Qwtdfh1gnyI+XqCgwzzt3/RPQxEcGXBdOWUM3iQ4V5fNxIGtA69/XN2s6oh7rhNy96vD52oA=[/tex][tex=0.786x1.286]q1djlrfSWHAqH21hBgtrSw==[/tex]的方向垂直纸面向里。