Multipole expansion - thin disc a thin disc of radius r is homogeneously charged with linear charge density o. find the potential on the symmetry axis of the disc far away (a) by explicitly solving laplace equation (b) by using the multipole expansion

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.

you have to draw the persons position over there