\(100 ×10^{-3 } = (0.5)  I_{max}\)

\({I_{\max }} = \,\,\frac{{100\,\, \times \,\,\,{{10}^{ - 3}}}}{{0.5}}\,\,\, = \,\,200\,\,mA\)

પરિપથને કિર્ચોફનો નિયમ લગાવતાં, \(V = I_{max } R + V_D\)

\(R\,\, = \,\,\frac{{V - {V_D}}}{{{I_{\max }}}}\,\, = \,\,\frac{{1.5 - 0.5}}{{200\,\, \times \,\,\,{{10}^{ - 3}}}}\,\,\, = \,\,\,\frac{{{{10}^3}}}{{200}}\,\,\,\,\,\,\,\therefore \,\,R\,\, = \,\,5\,\Omega \,\)