Digital Logic


Q51.

In the following truth table, V = 1 if and only if the input is valid. What function does the truth table represent?
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Q52.

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
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Q53.

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.
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Q54.

A multiplexer is placed between a group of 32 registers and an accumulator to regulate data movement such that at any given point in time the content of only one register will move to the accumulator. The number of select lines needed for the multiplexer is ______.
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Q55.

The logic operations of two combinational circuits in Figure-I and Figure -II are
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Q56.

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 ________ .
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Q57.

The circuit given in the figure below is
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Q58.

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.
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Q59.

A Boolean digital circuit is composed using two 4-input multiplexers (M1 and M2) and one 2-input multiplexer (M3) as shown in the figure. X0-X7 are the inputs of the multiplexers M1 and M2 and could be connected to either 0 or 1. The select lines of the multiplexers are connected to Boolean variables A, B and C as shown.Which one of the following set of values of (X0, X1, X2, X3, X4, X5, X6, X7) will realise the Boolean function \bar{A}+\bar{A}\cdot \bar{C}+A\cdot \bar{B}\cdot C ?
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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
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