\(OB\,\, = \,\,OC\,\) \(\cos \,\,45^\circ \) અને \(OA\, = \,\,OC\) \(\sin \,\,45^\circ \)
\( \Rightarrow \,\,OC\,\, = \,\,\frac{{10}}{{\sin \,\,45^\circ }}\,\, = \,\,10\,\sqrt 2 \,N\,\,\, \Rightarrow \,\,OB\)
\( = \,\,\left( {10\sqrt 2 } \right)\,\,\left( {\frac{1}{{\sqrt 2 }}} \right)\,\, = \,\,10N\)