Placed in the origin, magnetic moment $$\vec{\mathfrak{m}}$$ produces at point $$\vec{R}_0$$ magnetic vector potential
$$\vec{A} = {\vec{\mathfrak{m}} \times \vec{R}_0 \over R_0^3}.$$(1)
Tikz Picture$$ \begin{tikzpicture}[domain=0:2] \draw[very thin] (-0.1,-0.1) grid (2.1,2.1); \draw[->] (-0.2,0)--(2.2,0) node[right] {$x$}; \draw[->] (0,-0.2)--(0,2.2) node[above] {$y$}; \draw plot (\x,{sin(\x r)}) node[right] {$y=\sin x$}; \draw[color=blue] plot (\x,\x) node[right] {$y=x$}; \end{tikzpicture} $$
$$ \ctikzset{ logic ports=ieee, logic ports/scale=0.7, } \tikzset{sr-ff/.style={flipflop, flipflop def={ t1=S, t2=CP, t3=R, t4={\ctikztextnot{Q}}, t6=Q, nd=1}}, } \begin{circuitikz}[] \draw (0,0) node[sr-ff](FF){} (FF.bup) node[above]{SR-FF}; \draw (FF.pin 1) -- ++(-1,0) node[and port, anchor=out](AND1){} (FF.pin 3) -- ++(-1,0) node[and port, anchor=out](AND2){}; \end{circuitikz} \begin{circuitikz}[scale=0.8, transform shape] \draw (0,0) node[sr-ff](FF){} (FF.bup) node[above]{SR-FF} (FF.pin 1) -- ++(-1,0) node[and port, anchor=out](AND1){} (FF.pin 3) -- (FF.pin 3 -| AND1.out) node[and port, anchor=out](AND2){} (AND1.in 1) to[short, -*] ++(-1,0) coordinate(in) to[inline not] (in |- AND2.in 2) -- (AND2.in 2); \end{circuitikz} \newcommand*{\myblock}[1]{% Add #1- to the node and coord names node[sr-ff](#1-FF){} (#1-FF.bup) node[above]{SR-FF} (#1-FF.pin 1) -- ++(-1,0) node[and port, anchor=out](#1-AND1){} (#1-FF.pin 3) -- (#1-FF.pin 3 -| #1-AND1.out) node[and port, anchor=out](#1-AND2){} (#1-AND1.in 1) to[short, -*] ++(-1,0) coordinate(#1-in) to[inline not] (#1-in |- #1-AND2.in 2) -- (#1-AND2.in 2) } \begin{circuitikz} \draw (0,0) \myblock{A}; \draw (0,-4) \myblock{B}; \draw (A-in) -- ++(-0.5, 0) node[ below]{$a_0$}; \draw (B-in) -- ++(-0.5, 0) node[ below]{$a_1$}; \draw (A-AND1.in 2) to[short, -*] (A-AND2.in 1) to[short, -*] (B-AND1.in 2) to[short, -*] (B-AND2.in 1) -- ++(0, -2) coordinate(down) node[below]{ENABLE}; \draw (A-FF.pin 2) to[short, -*] (B-FF.pin 2) -- (B-FF.pin 2 |- down) node[below]{CP}; \draw (B-FF.down) to[short, -*] ++(0,-0.3) coordinate(dd); \draw (A-FF.down) -- ++(0,-.5) -- ++(1.5,0) |- (dd) -- (dd |- down) node[below]{RESET}; \end{circuitikz} $$