Hai dòng điện có cường độ I1=2A, I2=4A chạy trong hai dây dẫn thẳng dài vô hạn, đồng phẳng, vuông góc với nhau đặt trong không khí.Trong mặt phẳng chứa hai dòng điện, quỹ tích những điểm tại đó vec tơ cảm ứng từ tổng hợp bằng 0 là đường thẳng( trừ điểm gốc tọa độ )):

Acommon technique in analysis of scientific data is normalization. the purpose of normalizing data is to eliminate irrelevant constants that can obscure the salient features of the data. the goal of this experiment is to test the hypothesis that the flux of light decreases as the square of the distance from the source. in this case, the absolute value of the voltage measured by the photometer is irrelevant; only the relative value conveys useful information. suppose that in part 2.2.2 of the experiment, students obtain a signal value of 162 mv at a distance of 4 cm and a value of 86 mv at a distance of 5.7 cm. normalize the students' data to the value obtained at 4 cm. (divide the signal value by 162.) then calculate the theoretically expected (normalized) value at 5.7 cm.