HP 50g Graphing, 48gII Graphing manual Straight Wire 7, Force between Wires 7

Straight Wire (7, 1)

The magnetic field calculation differs depending upon whether the point is inside or outside the wire.

Equation:

B= ∝ 0 ⋅ ∝ r ⋅ I 2 ⋅ π ⋅ r

Example:

Given: ∝r=1, rw= 0.25_cm, r=0.2_cm, I=25_A.

Solution: B= 0.0016_T.

Force between Wires (7, 2)

The force between wires is positive for an attractive force (for currents having the same sign).

Equation:

Fba = ∝ 0 ⋅ ∝ r ⋅ L ⋅ Ib ⋅ Ia 2 ⋅ π ⋅ d

Example:

Given: Ia=10_A, Ib=20_A, ∝r=1, L=50_cm, d=1_cm.

Solution: Fba=2.0000E–3_N.

532 Equation Reference