- #1

- 270

- 5

## Main Question or Discussion Point

In Griffith's EM text, he devouts 2 pages to deriving the equation for bound currents, and for the next 4 problems, he (the solution manual) doesn't even use the equations just introduced. I question the wisdom of deriving an equation that is harder to work with than we already had.

$$\vec{A}(\vec{r}) = \frac{\mu _0}{4 \pi} ( \int _V \frac{\vec{J}_b}{r'}dV' + \oint _S \frac{\vec{K}_b}{r'}da')$$

When using this, I always get a really really ugly integral that would be too messy to work with. I guess it has some worth from a theoretical stand point, but I don't really understand why the questions that proceed this don't use the material from the same section.

$$\vec{A}(\vec{r}) = \frac{\mu _0}{4 \pi} ( \int _V \frac{\vec{J}_b}{r'}dV' + \oint _S \frac{\vec{K}_b}{r'}da')$$

When using this, I always get a really really ugly integral that would be too messy to work with. I guess it has some worth from a theoretical stand point, but I don't really understand why the questions that proceed this don't use the material from the same section.