$\begin {array} {1 1} (a)\;Value\: of\: current \\ (b)\;Length\: of\; the\: element \\ (c)\;Distance \: from\: the\: element\: and\: the \: direction\: of\: position \: vector\: relative\: to\: the\: element \\ (d)\;All\: of \: the \: above \end {array}$