Q91

Q91. Three infinitely long change sheets are placed as shown in figure. The electric field at point P is 

                                      

            $\left(\mathrm{a}\right) \frac{2\mathrm{\sigma }}{{\mathrm{\epsilon }}_0}\hat{\mathrm{k}} \left(\mathrm{b}\right) -\frac{2\mathrm{\sigma }}{{\mathrm{\epsilon }}_0}\hat{\mathrm{k}} \left(\mathrm{c}\right) \frac{4\mathrm{\sigma }}{{\mathrm{\epsilon }}_0}\hat{\mathrm{k}} \left(\mathrm{d}\right)-\frac{4\mathrm{\sigma }}{{\mathrm{\epsilon }}_0}\hat{\mathrm{k}}$