a)\(B_1=4\pi\cdot10^{-7}\cdot\dfrac{I_1}{r_1}=4\pi\cdot10^{-7}\cdot\dfrac{9}{0,2}=5,65\cdot10^{-8}T\)
\(B_2=4\pi\cdot10^{-7}\cdot\dfrac{I_2}{r_2}=4\pi\cdot10^{-7}\cdot\dfrac{16}{0,3}=6,7\cdot10^{-5}T\)
Nhận thấy hai dây cùng chiều:
\(\Rightarrow B=B_1+B_2=5,65\cdot10^{-5}+6,7\cdot10^{-5}=12,35\cdot10^{-7}T\)
b)\(B_1=4\pi\cdot10^{-7}\cdot\dfrac{I_1}{r_1}=4\pi\cdot10^{-7}\cdot\dfrac{9}{0,3}=3,8\cdot10^{-5}T\)
\(B_2=4\pi\cdot10^{-7}\cdot\dfrac{I_2}{r_2}=4\pi\cdot10^{-7}\cdot\dfrac{16}{0,4}=5,03\cdot10^{-5}T\)
Nhận thấy \(B=\sqrt{B_1^2+B_2^2}\)
\(\Rightarrow B=\sqrt{\left(3,8\cdot10^{-5}\right)^2+\left(5,03\cdot10^{-5}\right)^2}=6,3\cdot10^{-5}T\)
Đúng 2
Bình luận (0)
