b
કોણીય પહોળાઈ \(\theta \,\, = \,\, \frac{\lambda }{d}\,\, \Rightarrow \,\,d\,\, = \,\,\frac{\lambda }{\theta }\,\, = \,\,\,\frac{{4800\,\, \times \,\,{{10}^{ - 10}} \times \,\,200}}{\pi }\,\,\)
\( = \,\,\,\left( {\frac{{9.6}}{\pi }} \right)\,\, \times \,\,{10^{ - 5}}\,\,radian\)