GATE PYQ

Digital Logic

Q51.
If there are m input lines and n output lines for a decoder that is used to uniquely address a byte addressable 1 KB RAM, then the minimum value of m+n is ________ .

Q52.
Which one of the following circuits implements the Boolean function given below?f(x,y,z) = m_0+m_1+m_3+m_4+m_5+m_6where m_i is the i^{th} minterm.

Q53.
Following Multiplexer circuit is equivalent to

Q54.
Minimum number of 2x1 multiplexers required to realize the following function, f=\bar{A} \bar{B} C+\bar{A} \bar{B} \bar{C}Assume that inputs are available only in true form and Boolean a constant 1 and 0 are available.

Q55.
Consider the following combinational function block involving four Boolean variables x, y, a, b where x, a, b are inputs and y is the output. f (x, y, a, b) { if (x is 1) y = a; else y = b; } Which one of the following digital logic blocks is the most suitable for implementing this function?

Q56.
The logic circuit given below converts a binary code y1, y2, y3 into

Q57.
The output of a 2-input multiplexer is connected back to one of its inputs as shown in the figure.Match the functional equivalence of this circuit to one of the following options.

Q58.
For a binary half-subtractor having two inputs A and B, the correct set of logical outputs D(=A minus B) and X(=borrow) are

Q59.
In the following truth table, V = 1 if and only if the input is valid. What function does the truth table represent?

Q60.
When two 8-bit numbers A_{7}....A_{0} and B_{7}....B_{0} in 2's complement representation (with A_{0} and B_{0} as the least significant bits ) are added using a ripple-carry Combinational Circuit, the sum bits obtained are S_{7}....S_{0} and the carry bits are C_{7}....C_{0}. An overflow is said to have occurred if