Find the monopoles, dipoles of the following charge distributions:
(a)
$\rho(r) = -q\delta(r - a\hat{z}) + 3q\delta(r + a\hat{z})$
(b) At $s = R$ and $z = 0$
$\lambda(\phi) = \lambda_0 \cos \phi$
(c) At $s = R$ and $z = 0$
$\lambda(\phi) = \lambda_0 \cos^2 \phi$
(d) At $r = R$,
$\sigma(\theta, \phi) = \sigma_0 \cos \theta$
(e) At $r = R$,
$\sigma(\theta, \phi) = \sigma_0 \sin^2 \theta \cos \phi$