A Si pn junction with zero applied bias has doping concentrations of ND = 5 x 105 cm and NA = 2 x 105 cm . 30) The ratio of WN/Wp is (A) 5 (B) 1/5 (C) 3/5 (D) 2/5 (E) None of the above 31) The built-in voltage is (A) 0.843 V (B) 0.773 V (C) 0.721 V 32) The depletion region width W is (A) 3.25 x 10 cm (B) 4.57 x 10 cm (C) 4.57 x 10 cm (D) 0.638 V (E) None of the above (E) None of the above (D) 3.25 x 10 cm 33) In depletion region, magnitude of maximum electric field Em is (A) 3.16x104 V/cm (B) 2. 65x104 V/cm (C) 2.15x104 V/cm (D) 1.47x10 V/cm (E) None of the above