1987
1.
Choose the correct statements
relating to the circuit of figure shown
Answer: B & D
Solution : https://www.youtube.com/watch?v=zryK-Yl3-Dg
Solution : https://www.youtube.com/watch?v=zryK-Yl3-Dg
1988
1.
The circuit given below is a
a.
JK flip flop
b.
Johnson counter
c.
RS latch
d.
None of the above
1991
1. An S-R flip flop can be converted into a T
flip flop by connecting ____ to Qbar and _____ to Q.
Answer: S to Qbar and R to Q
Solution : https://www.youtube.com/watch?v=sxSeKlxdxSc
1992
1.
A new clocked X-Y flip flop is
defined with two inputs, X and Y is in addition to the clock input. The flip
flop functions as follows:
If XY = 00, the flip flop changes state with each clock
pulse
If XY = 01, the flip flop state Q becomes ‘1’ with the next
clock pulse
If XY = 10, the flip flop state Q becomes ‘0’ with the next
clock pulse
If XY = 11, the change of state occurs with the clock pulse
a.
Write the truth table for the XY
flip flop
b.
Write the excitation table for the
XY flip flop
c.
It is desirable to convert a J-K
flip flop into X-Y flip flop by adding some external gates, if necessary. Draw a circuit to show how you will
implement in X-Y flip flop using a J-K
flip flop.
Solution : https://www.youtube.com/watch?v=c8PZBGHCGDQ
1994
1. For the digital circuit shown in the figure, explain what
happens at nodes N1, N2, F and F’ when
Solution : https://www.youtube.com/watch?v=yl2GD3Hetm8
1995
1.
A switch-tail ring counter is made
by using a single D flip flop. The resulting circuit is a
a.
SR flip flop
b.
JK flip flop
c.
D flip flop
d.
T flip flop
Answer: D
Solution : https://www.youtube.com/watch?v=NgHdSqy1YKw
2.
An SR latch is a
a.
Combinational circuit
b.
Synchronous sequential circuit
c.
One bit memory element
d.
One clock delay element
Answer: C
Solution : https://www.youtube.com/watch?v=C8x2OcVIKh8
1997
1.
In a JK flip flop, we have J = Q’
and K = 1. Assume the flip flop was initially cleared and then clocked for 6
pulses, the sequence at the Q output will be
a.
010000
b.
011001
c.
010010
d.
010101
1998
1.
In the figure shown is A = 1 and B =
1, the input B is now replaced with a
sequence 101010....., the output X and Y will be
a.
Fixed at 0 and 1 respectively
b.
X = 1010... while Y = 0101....
c.
X = 1010.... and Y = 1010....
d.
Fixed at 1 and 0 respectively
Answer: A
2000
1.
A sequential circuit using D flip
flop and logic gates is shown in figure, where X and Y are the inputs and Z is
output. The circuit is
a.
S-R flip flop with inputs X = R and
Y = S
b.
S-R flip flop with inputs X = S and
Y = R
c.
J-K flip flop with inputs X = J and
Y = K
d.
J-K flip flop with inputs X = K and
Y = J
Answer: D
Solution :
https://www.youtube.com/watch?v=Z9naO48RJT8
2001
1.
In the figure, the output of the
oscillator, V1 has 10 volts peak amplitude with zero DC value. The
transfer characteristic of the Schmitt inverter is also shown in the figure.
Assume that the JK flip-flop is reset at time t=0.
a.
What is the period and duty cycle of
the waveform V2?
b.
What is the period and duty cycle of
the waveform V3?
c.
Sketch V1, V2
and V3 for the duration 0 ≤ t ≤ 6 µsec. Clearly indicate the exact timings when the waveforms V2
and V3 make high to low and low to high transitions.
2004
1.
A Master – Slave flip flop has the
characteristic that
a.
Change in the input immediately
reflected in the output.
b.
Change in the output occurs when the
state of the master is affected
c.
Change in the output occurs when the
state of the slave is affected
d.
Both the master and the slave states
are affected at the same time.
Answer: C
Solution : https://www.youtube.com/watch?v=oViyDQttV2E
2005
1. The present output Qn of an edge triggered JK
flip-flop is logic ‘0’. If j = 1, then Qn+1 is
a.
Cannot be determined
b.
Will be logic ‘0’
c.
Will be logic ‘1’
d.
Will race around
Answer: C
Solution : https://www.youtube.com/watch?v=3Txg02Wb8N0
2007
1. In the following circuit, binary values were applied to the
inputs X and Y inputs of the NAND latch shown in the figure in the sequence
indicated below:
X = 0, Y =
1; X = 0, Y = 0; X = 1, Y = 1;
The corresponding stable P, Q outputs will be
Answer: C
2008
1. For the circuit shown in the figure, D has a transition from
0 to 1 after CLK changes from 1 to 0. Assume gate delays to be negligible.
Which of the following statements is TRUE?
a.
Q goes to 1 at the CLK transition
and stays at 1
b.
Q goes to 0 at the CLK transition
and stays at 0
c.
Q goes to 1 at the CLK transition
and goes to 0 when D goes to 1
d.
Q goes to 0 at the CLK transition
and goes to 1 when D goes to 1
Answer: C
2009
1. Refer to the NAND and NOR latches shown in the figure. The
inputs (P1, P2) for both the latches are first made (0,
1) and then, after a few seconds, made (1, 1). The corresponding stable outputs
(Q1, Q2) are
Answer: C
Solution : https://www.youtube.com/watch?v=CmdmJ9qQjdk
2012
1. Consider the given circuit. In the circuit, the race around
Answer: A
Solution : https://www.youtube.com/watch?v=VGgKVxbWrfw
Great
ReplyDeleteThank you
Complete the binary sequence at Q until 6 clock pulses with the aid of table. Assume that the
ReplyDeleteflip-flop was initially cleared and J = 1, K = Q.
CAN YOU EXPLAIN THE TRUTH TABLE