B.Sc. I (Semester Examination, 2018
(CBCS Pattern)
Electronics (Paper
Digital Electronics I
Day and Date Friday, 2-11-2018 Max. Marks 70
Time 10.30 a.m. to 1.00 p.m.
Instructions All questions are compulsory.
Figures to the right indicate full marks.
Draw circuit diagram wherever necessary.
1. Multiple choice questions 14
IC 7402 is type gate.
NOR NAND OR XOR
IC is an encoder.
74148 74138 74154 74151
Half adder uses gate.
AND, XOR OR, NAND AND, NOT OR, XOR
Base of hexadecimal no. system is
2 4 8 16
IC is counter.
7495 7490 74138 74150
Race around condition occurs in flip flop.
JK RS D None of these
The excess 3 code of 5 is
1111 1010 1000 0101
is circuit with one input and many output.
multiplexer demultiplexer
encoder decoder
BCD equivalent for 75 is
01110100 01111000 01110101 01010111
10) Toggling occurs in JK flip flop for input
1 0 1 0
11) no. of flip flops are used to store 4 bits.
1 2 3 4
12) Full adder is used to make addition of bits.
2 3 4 8
13) Total no. of gates in IC 7404 are
2 3 4 6
14) The AND gate is gate.
basic universal inverter none of these
2. Answer the following (any four) 8
Explain octal no. system.
Write binary rules for multiplication.
Draw logic diagram of half adder.
Explain concept of race condition.
Explain ones compliment with example.
Write note on (any two) 6
Explain excess 3 code.
Explain 3 variable K-map.
Explain D flip flop.
3. Answer the following (any two) 8
Explain D Morgan's theorem.
Explain parity check error detection.
Explain ring counter.
Answer the following (any one) 6
Explain basic gate with symbol.
Explain K-map for 4 variables.
4. Answer the following (any two) 10
Explain hexadecimal no. system.
Explain full adder with diagram.
Explain 3 bit up counter.
Answer the following (any one) 4
Explain mod 10 counter.
Explain binary to decimal conversion.
5. Answer the following (any two) 14
Explain RS flip flop using NAND and NOR gate.
Explain universal adder/sub tractor.
Explain hexadecimal to binary and binary to hexadecimal conversion.