33
punti
Livello 0
B = μo * i /(2πr); Legge sperimentale di Biot e Savart.
ko = μo/2π = 2 * 10^-7 N /A^2;
B = ko * i / r
B risultante = ko i1 / r1 + ko i2 / r2 + ko i3/r2;
r1 = 2,0 cm = 2,0 * 10^-2 m; r2 = 5,0 cm; r3 = 8,0 cm
In A:
B1 entrante in A; B2 uscente in A; B3 entrante in A;
B1 = 2 * 10^-7 * 1,0 /(2,0 * 10^-2); entrante (+)
B2 = 2 * 10^-7 * 2,0 /(5,0 * 10^-2); uscente (-)
B3 = 2 * 10^-7 * 4,0 /(8,0 * 10^-2); entrante (+);
B(in A) = B1 - B2 + B3 ;
B (in A) = 2 * 10^-7 * [1,0 /(2,0 * 10^-2) - 2,0 /(5,0 * 10^-2) + 4,0 /(8,0 * 10^-2)];
B (in A) = 2 * 10^-7 * [50 - 40 + 50] = 2 * 10^-7 * 60;
B(in A) = 1,2 * 10^-5 T = 12,0 μT; entrante in A
86896
punti
Genius II