b
\(\overrightarrow E \,\,\, = \,\,\frac{{q\overrightarrow r }}{{4\pi \,\,{ \in _0}\,\,{r^3}}};\,\,\overrightarrow r \,\, = \,\,x\hat i\,\, + \,\,y\hat j\,\, = \,\,\sqrt 2 \hat i\,\, + \;\,\sqrt 7 \hat j\)

\(\overrightarrow E \,\, = \,\,\frac{{9\,\, \times \,\,{{10}^5}\,\, \times \,\,9\,\, \times \,\,{{10}^{ - 9}}\,\,\left( {\sqrt 2 \hat i\,\, + \,\,\sqrt 7 \hat j} \right)}}{{{{\left( 3 \right)}^3}}}\,\, = \,\,\left( {3\sqrt 2 \hat i\,\, + \;\,3\sqrt 7 \hat j} \right)\,\,N{C^{ - 1}}\)