Magnetic wire force changes with field and finite direction. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

One tesla gives eight newtons

Field 1 T, current 2 A, and length 4 m give force 8 N with direction up.

F=1×2×4=8F=1\times2\times4=8
Magnetic wire forceA perpendicular current and field set a sideways force.B=1 TI=2 AL=4 mF=8 NB=1 TI=2 AL=4 mF=8 N

Doubling field doubles the force

Field 2 T, current 2 A, and length 4 m give force 16 N with direction up.

F=2×2×4=16F=2\times2\times4=16
Magnetic wire forceA perpendicular current and field set a sideways force.B=2 TI=2 AL=4 mF=16 NB=2 TI=2 AL=4 mF=16 N

Reversing current flips direction, not size

Field 2 T, current 2 A, and length 4 m give force 16 N with direction down.

F=2×2×4=16F=2\times2\times4=16
Magnetic wire forceA perpendicular current and field set a sideways force.B=2 TI=2 AL=4 mF=16 NB=2 TI=2 AL=4 mF=16 N