DipIETE – CS (OLD SCHEME)

Code: DC02                                                   Subject: FUNDAMENTALS OF ELECTRONICS

Time: 3 Hours                                                                                                     Max. Marks: 100

NOTE: There are 9 Questions in all.

· Question 1 is compulsory and carries 20 marks. Answer to Q. 1. MUST BE WRITTEN IN THE SPACE PROVIDED FOR IT in the answer book supplied and nowhere else.

· Out of the remaining EIGHT Questions answer any FIVE Questions. Each question carries 16 marks.

· Any required data not explicitly given, may be suitably assumed and stated.

Q.1       Choose the correct or the best alternative in the following:                                 (2 10)

a. The fourth colour band on the extreme right in general purpose fixed resistors represents

(A)  First significant digit.                     (B)  Tolerance.

(C)   Wattage rating.                            (D)  Voltage rating.

b. The donor type semiconductor is formed by adding impurity of valency

(A) 3.                                                 (B)  4.

(C)  5.                                                 (D)  6.

             c.   Which of the following diodes can be used in digital circuits?

(A) Varactor diode.                            (B) Tunnel diode.

(C) Zener diode.                                  (D) Schottky diode.

             d.   One of the following oscillator type provides extremely stable output frequency is

(A) Hartley oscillator.                         (B)  Wein bridge oscillator.

(C) Crystal oscillator.                          (D)  Clapp oscillator.         

             e.   Which statement is wrong related to an ideal op-amp?

(A) Bandwidth is infinite.                     (B)  CMRR is infinite.

(C)  Output impedance is infinite.         (D)  Gain is infinite.

             f.    The output is logic ‘1’ for like inputs & logic ‘0’ for unlike inputs. This statement is representative of which logic gate?

(A) AND                                           (B)  OR

(C)  NAND                                        (D)  EX-NOR

             g.   Which statement is correct for DeMorgan’s theorem?

(A) (B)

(C) (D)

             h.   Which transistor configuration has the highest input resistance?

(A)  Common emitter.

                   (B)  Common collector.

(C)  Common base.

(D)  Both common emitter & common base.

             i.    Conduction electrons have more mobility than holes because they

(A)  are lighter.

(B) have negative charge.

(C) needs less energy to move them.

(D) experience collision less frequently.

             j     In monolithic ICs, all the components are fabricated by

(A) diffusion process (B) evaporation process

(C) oxidation process (D) sputlering process

Answer any FIVE Questions out of EIGHT Questions.

Each question carries 16 marks.

Q.2     a.   What are Active and Passive components? Give two examples of each.              (8)

             b.   Explain how a voltage source is converted into a current source and a current source into a voltage source with neat diagrams.                              (8)

Q.3     a.   Differentiate between insulators, semiconductors and conductors on the basis of energy-band diagram.                                                                  (8)

             b.  What is the effect of heat on conductivity of intrinsic semicondutor?                     (8)

Q.4     a.   Explain how zener diode can be used as voltage regulator.                                (10)

b.   What is LED? Give its merits & demerits.                                                           (6)

Q.5     a.   Draw the circuit of transistor in common emitter configuration. Sketch the output characteristics indicating active, saturation & cut-off region.        (10)

             b.   Why silicon type transistors are  more often used than germanium type?              (6)

  Q.6     a.   Explain merits & demerits of FET over BJT and define JFET parameters.           (8)

             b.   Define CMRR & Slew rate.                                                                               (4)

             c.   Differentiate between SSI, MSI, LSI, VLSI on the basis of gates/chip.                (4)

Q.7     a.   What is the significant difference between the construction of an enhancement type MOSFET & a depletion type MOSFET?                                                                                                 (8)

b.    Draw the schematic diagram of an op-amp connected as

       (i) Inverting amplifier     (ii) Integrator.                                                                (8)

Q.8       a.   Define the following terms related to digital ICs

(i) Fan-out                                           (ii) Figure of merit                                    (4)

b.    How NOR gates can be used to obtain basic logic gates?                                  (6)

    c.     Write the truth table of half-adder circuit & design it using basic gates. (6)

Q.9       a. Simplify the following Boolean function in

                   (i)  Sum of Products                            (ii) Product of Sums.                                              

(8)

             b.  Explain the operation of DTL NAND gate.                                                         (8)