This document is an introduction to digital electronics question paper from April 2014. It contains 7 questions testing knowledge of digital concepts like binary, hexadecimal, and octal conversions; logic gates; adders; flip flops; encoders and decoders; multiplexers and demultiplexers; and transistors. Students are instructed to answer question 1 and 4 of 7 total questions. The questions cover topics ranging from basic logic gates to semiconductor characteristics.

1. I n t r o d u c t i o n T o D i g i t a l E l e c t r o n i c s
Q u e s t i o n P a p e r ( A p r i l – 2 0 1 4 ) [ O l d C o u r s e ]
1 | Page
M u m b a i B . S c . I T S t u d y
F a c e b o o k | T w i t t e r | I n s t a g r a m | G o o g l e + | Y o u T u b e
– Kamal T.
Time: 3 Hours Total Marks: 100
N.B.: (1) Questions No. 1 is Compulsory.
(2) Answer any four from the Remaining Questions.
(2) All Questions carry Equal Marks.
Q.1 Attempt Both The Question: (20 Marks)
(A) Do the following Conversion:
(i) (11111.10001)2 = (? )10
(ii) (𝐹𝐵𝐴. 𝐵𝐶)16 = (? )10
(iii) (486.524)10 = (? )2
(iv) (465.32)8 = (? )10
(v) (1101.1011)2 = (? )10
(10)
(B) Explain Basic Logic Gates with their symbols and truth tables. (10)
Q.2 Attempt The Following Questions: (20 Marks)
(A) (i) Write the BCD code for 9248.
(ii) Write the Excess-3 code for (35)10
(iii) Convert binary 1111 to gray code.
(6)
(B) Subtract using Two’s Complement
(1) (6-8)
(2) (7-4)
(6)
(C) Explain the clocked S-R Flip Flop in detail. (8)
Q.3 Attempt The Following Questions: (20 Marks)
(A) Explain the formation of AND, OR and NOT Gate using Universal Gates. (10)
(B) Minimize the following expression using K-Map and realize using Basic Gates.
𝑓(𝐴, 𝐵, 𝐶, 𝐷) = ∑ 𝑚 (1, 3, 5, 7, 8, 9, 10, 11, 13, 15)
(10)
Q.4 Attempt The Following Questions: (20 Marks)
(A) Explain Full adder and half adder in detail with circuit diagram and truth table. (10)
(B) State & prove Demorgan’s both laws. (10)
Q.5 Attempt The Following Questions: (20 Marks)
(A) Write a short note on decoder. (5)
(B) Explain Master Slave Flip-Flop with suitable diagram. (7)
(C) Explain the term Shift Register with their types in detail. (8)

2. I n t r o d u c t i o n T o D i g i t a l E l e c t r o n i c s
Q u e s t i o n P a p e r ( A p r i l – 2 0 1 4 ) [ O l d C o u r s e ]
2 | Page
M u m b a i B . S c . I T S t u d y
F a c e b o o k | T w i t t e r | I n s t a g r a m | G o o g l e + | Y o u T u b e
– Kamal T.
Q.6 Attempt The Following Questions: (20 Marks)
(A) What is Multiplexer? Design 8:1 Multiplexer Circuit with its Logic Equation and truth
table.
(10)
(B) What is semiconductor? Write down the characteristics of semiconductor. (10)
Q.7 Attempt The Following Questions: (20 Marks)
(A) Explain the term transistor as an amplifier with the circuit diagram. (10)
(B) Write a short note on Demultiplexer with the working of 4:1 Demultiplexer. (10)