Computer Science - Digital Electronics
Exam Duration: 45 Mins Total Questions : 30
2's complement of a 16-bit number (one sign and 15 magnitude bits) in FFF, its magnitude in decimal representation is
- (a)
0
- (b)
1
- (c)
23767
- (d)
6453.5
The binary representation of number (10)4 is
- (a)
(1101010010000)2
- (b)
(1111000011010)2
- (c)
(101010011000)2
- (d)
(10111111111)2
Binary representation of number (1998)10 is
- (a)
(101011001100)2
- (b)
(11111001110)2
- (c)
(1011001100)2
- (d)
(1010101010)2
Excess-3 code for (45)10 is
- (a)
0111 1001
- (b)
0111 1010
- (c)
0111 1000
- (d)
1010 1010
What will be the reduced value of function ((AB)' A(AB)' B)?
- (a)
AB + BC
- (b)
BA + AB
- (c)
\(\bar { B } A+\bar { A } \bar { B } \)
- (d)
\(\bar { B } A+\bar { A } B\)
What happens if a bit string is XORed with itself n-times as shown,
\(A\bigoplus B\bigoplus B\bigoplus ....n\quad times\)
- (a)
complements when n is even
- (b)
complement when n is odd
- (c)
devides by 2n always
- (d)
remains unchange when n is odd
State whether true or false
The look-ahead carry adder in the parallel carry adder where all sum digits are generated directly from the input digits
- (a)
false
- (b)
true
- (c)
can't say
- (d)
data insufficient
When two n-bit binary numbers are added the sum will contain at the most
- (a)
n bits
- (b)
(n+1) bit
- (c)
(n+2) bit
- (d)
(n+3) bit
When an odd number is converted into binary number the LSB is
- (a)
0
- (b)
1
- (c)
0 or 1
- (d)
None of these
BCD addition of A(0101) and B(0110) gives
- (a)
1001
- (b)
1011
- (c)
1000
- (d)
None of these
ASCII code is
- (a)
4-bit code
- (b)
6-bit code
- (c)
8-bit code
- (d)
7-bit code
(60)10 + (F1)16 - (1001001)2 =
- (a)
(108)10
- (b)
(16D)16
- (c)
(228)10
- (d)
(161)8
XOR is
- (a)
odd function
- (b)
even function
- (c)
Both a and b
- (d)
None of these
The given expression \(Y=\overline { \overline { \overline { AB } +ABC } +A\left( B+A\bar { B } \right) } \) can be reduced to
- (a)
1
- (b)
A
- (c)
\(\bar { A } \)
- (d)
\(\overline { AB } \)
A logical function of three variables is given as
\(f\left( A,B,C \right) =Y=\left( \bar { A } +B+C \right) \left( A+C \right) \left( \bar { A } +\bar { B } \right) \)
The canonical POS form is
- (a)
\(\pi \left( 1,3,9,1 \right) \)
- (b)
\(\pi \left( 2,3,5,8 \right) \)
- (c)
\(\pi \left( 0,2,6,7 \right) \)
- (d)
\(\pi \left( 1,2,8,10 \right) \)
Match the following:
(a) Encoder | 1. One of many |
(b) Demux | 2. Some of many |
(c) Decoder | 3. Many to some |
- (a)
a-1, b-2, c-3
- (b)
a-3, b-1, c-2
- (c)
a-1, b-2, c-3
- (d)
None of these
Which one of the following are called universal gates?
- (a)
AND, OR, NOT
- (b)
XOR AND XNOR
- (c)
NAND and NOR
- (d)
NAND and AND
Which one of the following stands for NOT operation?
- (a)
dot
- (b)
plus
- (c)
overbar
- (d)
None of these
The output of XOR gate is.........
- (a)
\(C=\overset { - }{ A } .B+A.\overset { - }{ B } \)
- (b)
\(C=\overset { - }{ A } .\overset { - }{ B } +A.B\)
- (c)
\(C=\overline { A.B } +A.B\)
- (d)
\(C=\overline { A+B } +\overline { A.B } \)
A simplest way to convent a truth table to a Boolean function is.......
- (a)
NOR of minterms
- (b)
OR minterms
- (c)
OR of maxterms
- (d)
XOR of minterms
A logical unit that adds two binary digits is called a.........
- (a)
full adder
- (b)
half adder
- (c)
logical gates
- (d)
gate adder
A full adder adds........binary digits.
- (a)
three
- (b)
two
- (c)
four
- (d)
five
A full adder sums.........input bits.
- (a)
3
- (b)
2
- (c)
5
- (d)
4
The full added can be constructed from...........
- (a)
two half address and NOT gate
- (b)
one half adder and OR gate
- (c)
two half adders and OR gate
- (d)
three half adders and OR gate
If the logic circuit outputs are base on the inputs, they are called.......
- (a)
sequential circuits
- (b)
combinational circuits
- (c)
digital circuits
- (d)
flip-flop circuit
Which one of the following circuits are capable of sorting one bit of information?
- (a)
Full adder
- (b)
Half adder
- (c)
Flip-flop
- (d)
Combinational circuit
A flip-flop circuit can be constructed using.............
- (a)
two NOR gates or two NAND gates
- (b)
one NOR gates and one NAND gates
- (c)
two NOR gates and one NAND gate
- (d)
one NOR gate or two NOT gates
Which one of the following is a simulation tool for electronic circuits?
- (a)
Logic gates
- (b)
Integrated circuits
- (c)
Electric workbench
- (d)
CPU
The included dot \((\odot )\)stands for........
- (a)
NOR
- (b)
XNOR
- (c)
XOR
- (d)
NAND
The shortcut key used to place the logic gates in the multisim workspace by........
- (a)
Ctrl+E
- (b)
Ctrl+W
- (c)
Ctrl+G
- (d)
Ctrl+L