EC www.gateforum.com © All rights reserved by Gateforum Educational Services Pvt. Ltd. No part of this booklet may be reproduced or utilized in any form without the written permission. Discuss this questions paper at www.gatementor.com. 1 Answer Keys 1 D 2 C 3 A 4 D 5 B 6 C 7 C 8 B 9 A 10 C 11 D 12 D 13 A 14 C 15 A 16 C 17 C 18 C 19 A 20 A 21 A 22 B 23 B 24 A 25 D 26 B 27 C 28 B 29 C 30 A 31 B 32 C 33 A 34 C 35 C 36 A 37 B 38 B 39 C 40 A 41 A 42 B 43 D 44 A 45 C 46 B 47 B 48 B 49 C 50 B 51 A 52 B 53 B 54 C 55 D 56 D 57 A 58 B 59 B 60 B 61 B 62 B 63 D 64 D 65 A 66 B 67 C 68 D 69 A 70 B 71 C 72 A 73 B 74 C 75 B 76 C 77 B 78 C 79 B 80 D 81 A 82 A 83 C 84 B 85 D 86 C 87 A 88 D 89 B 90 C 91 A 92 D 93 D 94 B 95 B 96 D 97 C 98 C 99 C 100 D 101 C 102 C 103 A 104 A 105 A 106 C 107 D 108 C 109 B 110 B 111 A 112 A 113 B 114 A 115 D 116 D 117 B 118 C 119 C 120 A Explanations:- 1. VA=2 x 2 +10 = 14V 2. 2 1 11 1 V 0 V h 2 I = = = Ω 4. eq eq R 4 ; C =(1F+1F)||2F=1 = Ω eq eq R C =4sec τ = 6. Given figure is for intrinsic semiconductor. With increase in temperature, equal number of holes and electrons will be generated. Thus Fermi-level will remain at same place. 8. ( ) 17 14 a d T Built in 2 10 i N N 10 ×10 V = V n = 0.0259 n = 0.63V n 1.5×10 ℓ ℓ 9. 2 20 4 4 i e 15 c h 2.25 10 2.25 10 n 9 10 P 2.5 2.5 10 × × = = = = × × 10. ( ) C B CBO I I 1 I = β + β + 11. 0 GE V 10 V 10 0.3 9.7V = − = − = 13. Generation rate of hole = generation rate of electron 14. 2 19 4 19 n n n dn dn I qD ,D 20cm / sec, 10 /cm ,n 1.6 10 dx dx − = = = = × 16. 2 V( S) 7 T. F X(S) S 5S 7 = = + + n ; W 7 = 17. ξ = n 2 W 5 ; ξ = = n W 5 /2 2.5