Jaypee Institute of Information Technology (JIIT) 2008 B.E Test 1 : Basic Electronic Devices & Circuits - Question Paper

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Subject : Basic Electronic Device¹ and Circuits Branches : ECE'CSIT'BT'BTDD Sem : 11

1.    (a) The barrier potential developed across an open-circujted /Adjunction aids the

flow of minority carriers fro both sides of the junction. Explain how the current due to this flow of charge carriers is counterbalanced.

(A) Explain why the reverse saturation current in a silicon diode is much smaller that that in a germanium diode.

(3 + 2*5)

2.    What is the meaning of dc (static) and ac (dynamic) resistance with reference to a /W-junction diode ? How do you calculate these resistances for a diode ? Using V-! characteristics of a typical diode, justify that dc resistance is greater than ac resistance.    (2 + 1 + 2 ^m 5)

3.    Assuming the diodes to be ideal in the circuit of Fig. 1, (a) derive the expressions for the output dc voltage across the load resistor Ri and the required PfV for each diode,

(b) taking V * 10 volts, Rt - R - 10 kO, calculate these values.    (3 + 2 = 5)