The Motor Effect (HSC SSCE Physics): Flashcards

$B = \frac{\mu_0 I}{2\pi r}$

$4\pi \times 10^{-7}$ T m A⁻¹

Concentric circular loops

Thumb=current direction, fingers curl=field direction

$F = \frac{\mu_0 I_1 I_2 \ell}{2\pi r}$

Attractive (wires pull together)

Repulsive (wires push apart)

$\frac{F}{\ell} = \frac{\mu_0 I_1 I_2}{2\pi r}$

$F_{\text{by 2 on 1}} = -F_{\text{by 1 on 2}}$

$2 \times 10^{-7}$ N m⁻¹ (for 1 A, 1 m apart)