Analog and Digital Electronics Past Paper 2015-2016 PDF

## MAULANA ABUL KALAM AZAD UNIVERSITY OF TECHNOLOGY, WEST BENGAL ### CS-301 ANALOG AND DIGITAL ELECTRONICS **Time Allotted:** 3 Hours **Full Marks:** 70 **Instructions:** - The questions are of equal value. - The figures in the margin indicate full marks. - Candidates are required to give their an...

## MAULANA ABUL KALAM AZAD UNIVERSITY OF TECHNOLOGY, WEST BENGAL ### CS-301 ANALOG AND DIGITAL ELECTRONICS **Time Allotted:** 3 Hours **Full Marks:** 70 **Instructions:** - The questions are of equal value. - The figures in the margin indicate full marks. - Candidates are required to give their answers in their own words as far as practicable. - All symbols are of usual significance. ### **GROUP A** **(Multiple Choice Type Questions)** **1. Answer any ten questions.** 1. A 2-transistor class B power amplifier is commonly called - (A) push-pull - (B) dual - (C) differential - (D) none of these 2. A stable multivibrator has - (A) no stable state - (B) one stable state - (C) two stable states - (D) none of these 3. Schmitt trigger circuit generates - (A) triangular wave - (B) square wave - (C) saw tooth wave - (D) none of these 4. A Wien-bridge oscillator has a frequency - (A) $\\frac{1}{2π√RC}$ - (B) $\\frac{1}{RC}$ - (C) $\\frac{1}{2RC}$ - (D) none of these 5. Which of the following oscillators is used at audio frequency? - (A) Crystal oscillator - (B) Hartley oscillator - (C) RC phase-shift oscillator - (D) Colpitts oscillator 6. A + A'B + B' is equal to - (A) A - (B) B' - (C) 1 - (D) 0 7. Negative feedback in an amplifier is - (A) reduced gain - (B) increased noise - (C) increased frequency and phase - (D) reduced bandwidth 8. How many minimum number of NOR gates is required to implement NAND gate? - (A) 3 - (B) 4 - (C) 5 - (D) 2 9. The digital logic family which has minimum power dissipation is - (A) TTL - (B) RTL - (C) DTL - (D) CMOS 10. If the input to T-flip-flop is 100 Hz signal, the final output of the three T-flip-flops in cascade is - (A) 1000 Hz - (B) 500 Hz - (C) 300 Hz - (D) 12.5 Hz 11. Which one is the sequential circuit? - (A) Multiplexer - (B) Decoder - (C) Encoder - (D) Counter 12. 8421 is a - (A) weighted code - (B) non-weighted code - (C) complementary - (D) none of these ### **GROUP B** **(Short Answer Type Questions)** **2. Answer any three questions.** - Implement Full-adder circuit using two Half-adders. Write the truth table of Half-subtractor. - What is Multiplexer? Why it called data selector? Write the important characteristics of digital IC. - Implement the function F(A,B,C) = ∑m(1,3,5,6) using decoder. What is the difference between combinational circuit and sequential circuit? - Draw and explain the operation of Monostable multivibrator using 555 Timer. - Draw and explain the Schmitt trigger circuit. ### **GROUP C** **(Long Answer Type Questions)** **3. Answer any three questions.** - (a) Write truth table, circuit diagram and timing diagram of SR flip-flop using NOR gate. - (b) Convert D flip-flop into JK flip-flop. - Explain the operation of a class-B push-pull power amplifier with a neat circuit diagram. Determine its collector circuit efficiency. Explain why even harmonics are not present in push-pull amplifier. - (a) Design and implement a comparator circuit, which can compare two 3 bit binary numbers. - (b) Simplify the Boolean function using Quine McClusky method. - F = (1, 3, 4, 5, 9, 10, 11)+Σ (6.8) - (c) Design a 3 bit binary parallel combined ADDER / SUBTRACTOR circuit. - What is the Barkhausen criterion for a feedback amplifier to function as an oscillator? Give a neat circuit diagram of Wien bridge oscillator and explain how it works. Find an expression for the frequency of oscillation of the astable multivibrator. - Write short notes on any three of the following: - Cross over distortion - Ring counter - Even parity generator and checker - 555 timer - CMOS Logic.