Đáp án: $a.B$=$1,18.10^{−4}T $
$b.B$=$3,92.10^{−5}T$
Giải thích các bước giải:
$B_{1} =2π10^{−7}\frac{I1}{R1} =2π10^{−7}\frac{10}{0,8} =7,85.10^{−5}T$
$B_{2} =2π10^{−7}\frac{I2}{R2} =2π10^{−7}\frac{10}{0,16} =7,85.10^{−5}T$
$a.B_{1}+B_{2} =7,85.10^{−5}+7,85.10^{−5}=1,18.10^{−4}T$
$b.|B_{1}-B_{2}| =|7,85.10^{−5}+7,85.10^{−5}|=3,92.10^{−5}T$