documentclass[tikz,border=3.14mm]{standalone}
usetikzlibrary{through,intersections}
begin{document}
begin{tikzpicture}
path (2,0) coordinate (A) (-2,0) coordinate (B)  (0,1)
coordinate (C) (0,0) coordinate (O);
node[draw,name path=circ] (Circ) at (O) [circle through={(C)}]{};
draw[name path=line] (A) -- (B);
draw[thick,blue,->,name intersections={of=circ and line,sort by=circ}] (intersection-1) -- (intersection-2);
end{tikzpicture}
end{document}

documentclass[tikz,border=3.14mm]{standalone}
usetikzlibrary{through,intersections}
begin{document}
begin{tikzpicture}
path (-45:2) coordinate (A) (135:2) coordinate (B)  (0,1)
coordinate (C) (0,0) coordinate (O);
node[draw,name path=circ] (Circ) at (O) [circle through={(C)}]{};
draw[name path=line] (A) -- (B);
draw[thick,blue,->,name intersections={of=circ and line,sort by=circ}] (intersection-1) -- (intersection-2);
end{tikzpicture}
end{document}