GATE CSE 1987

Question 1
The Boolean expression A \oplus B \oplus A is equivalent to
A
AB + \bar {A}\bar B
B
\bar{A}B+A\bar{B}
C
B
D
\bar{A}
Digital Logic   Boolean Algebra
Question 2
The below figure shows four D-type flip-flops connected as a shift register using a XOR gate. The initial state and three subsequent states for three clock pulses are also given.


\begin{array}{|c|c|c|c|c|} \hline \text{State} & Q_{A} & Q_{B} & Q_{C} & Q_{D} \\\hline \text{Initial} & 1 & 1 & 1 & 1 \\\hline \text{After the first clock} & 0 & 1 & 1 & 1 \\\hline \text{After the second clock} & 0 & 0 & 1 & 1 \\\hline \text{After the third clock} & 0 & 0 & 0 & 1 \\\hline \end{array}

The state Q_{A} Q_{B} Q_{C} Q_{D} after the fourth clock pulse is
A
0000
B
1111
C
1001
D
1000
Digital Logic   Sequential Circuit
Question 3
Fig. below shows the circuit diagram of a wien bridge oscillator using an op-amp.

The frequency of oscillation is given by f= 1/2 \pi CR. To have the system oscillate the ratio R_{2}/R_{1} should be
A
0.5
B
29
C
2
D
Any value
Digital Logic   Combinational Circuit
Question 4
A Boolean function f is to be realized only by NOR gates. Its K-map is given below:

The realization is

A
A
B
B
C
C
D
D
Digital Logic   Boolean Algebra
Question 5
The refreshing rate of dynamic RAMs is in the range of
A
2 microseconds
B
2 milliseconds.
C
50 milli seconds
D
500 milliseconds
Computer Organization   Memory Chip Design
Question 6
The data transfer rate of a double-density floppy disk system is about:
A
5K bits/sec
B
50K bits/sec
C
500K bits/sec
D
5000K bits/sec
Computer Organization   Secondary Storage
Question 7
In a compiler the module that checks every character of the source text is called:
A
The code generator.
B
The code optimiser.
C
The lexical analyser.
D
The syntax analyser.
Compiler Design   Lexical Analysis
Question 8
A context-free grammar is ambiguous if:
A
The grammar contains useless non-terminals.
B
It produces more than one parse tree for some sentence.
C
Some production has two non terminals side by side on the right-hand side.
D
None of the above.
Theory of Computation   Context Free Grammar
Question 9
FORTRAN is a:
A
Regular language.
B
Context-free language.
C
Context-senstive language.
D
None of the above.
   
Question 10
An operator precedence parser is a
A
Bottom-up parser.
B
Top-down parser.
C
Back tracking parser.
D
None of the above.
Compiler Design   Parsing
There are 10 questions to complete.

Leave a Comment

Like this FREE website? Please share it among all your friends and join the campaign of FREE Education to ALL.