[" 27.If a circle passes through the point "(a,b)" and cuts the circle "x^(2)+y^(2)=p^(2)" orthogonally,"],[" of the locus of its centre is- "],[[" (1) "x^(2)+y^(2)-3ax-4by+(a^(2)+b^(2)-p^(2))=0," (2) "2ax+2by-(a^(2)-b^(2)+p^(2))=0],[" (3) "x^(2)+y^(2)-2ax-3by+(a^(2)-b^(2)-p^(2))=0," (4) "2ax+2by-(a^(2)+b^(2)+p^(2))=0]]