Consider a Boolean gate (D) where the output Y is related to the inputs A and b as, Y = A + $$\overline B $$, where + denotes logical OR operation. The Boolean inputs '0' and '1' are also available separately. Using instances of only D gates and inputs '0' and '1', ___________ (select the correct options).
A
NAND logic can be implemented
B
OR logic cannot be implemented
C
NOR logic can be implemented
D
AND logic cannot be implemented
2
GATE ECE 2018
Numerical
+2
-0
The logic gates shown in the digital circuit below use strong pull-down nMOS transistors for
LOW logic level at the outputs. When the pull-downs are off, high-value resistors set the
output logic levels to HIGH (i.e. the pull-ups are weak). Note that some nodes are
intentionally shorted to implement “wired logic”. Such shorted nodes will be HIGH only if
the outputs of all the gates whose outputs are shorted are HIGH.
The number of distinct values of X3X2X1X0 (out of the 16 possible values) that give
𝑌 = 1 is _______.
Your input ____
3
GATE ECE 2015 Set 3
MCQ (Single Correct Answer)
+2
-0.6
A universal logic gate can implement any Boolean function by connecting sufficient number of
them appropriately. Three gates are shown.
Which one of the following statesments is TRUE?
A
Gate 1 is a universal gate.
B
Gate 2 is a universal gate.
C
Gate 3 is a universal gate.
D
None of the gates shown is a universal gate.
4
GATE ECE 2015 Set 1
Numerical
+2
-0
All the logic gates shown in the figure have a propagation delay of 20 ns. Let A = C = 0 and B = 1
until time t = 0. At t = 0, all the inputs flip (i.e., A = C = 1 and B = 0) and remain in that state. For
t > 0, output Z = 1 for a duration (in ns) of ______________.
