Combinational Logic Analysis MCQs

Question 1

How many 2-input NOR gates does it take to produce a 2-input NAND gate?

Accepted Answer

4

Answer

1

Answer

2

Answer

3

Question 2

A logic circuit with an output X = ABC + AB consists of ________.

Accepted Answer

two AND gates, one OR gate, two inverters

Answer

two AND gates, two OR gates, two inverters

Answer

three AND gates, two OR gates, one inverter

Answer

two AND gates, one OR gate

Question 3

Assume you have A, B, C, and D available but not their complements. The minimum number of 2-input NAND gates required to implement the equation X = AB + BC is ________.

Accepted Answer

5

Answer

3

Answer

4

Answer

6

Question 4

A gate can drive a number of load gate inputs up to its specified ________.

Accepted Answer

fan-out

Answer

supply voltage

Answer

supply voltage

Answer

fan-in

Question 5

The expression AB + CD can be directly implemented using only ________.

Accepted Answer

an XNOR gate

Answer

an XOR gate

Answer

three 2-input NAND gates

Question 6

If both inputs of a 2-input NOR gate are connected, the gate will function as an ________.

Accepted Answer

AND gate

Answer

OR gate

Answer

any of the above

Question 7

Assume that you have a 3-input NAND gate but need only a 2-input gate. The unused input should be ________.

Accepted Answer

connected to a HIGH

Answer

connected to ground

Answer

left open

Answer

any of the above

Question 8

A node is defined as ________.

Accepted Answer

A node is defined as ________.

Answer

a circuit implemented as a sum-of-products

Answer

the output signals from a circuit

Answer

a shorted input

Question 9

Using the universal property of a NAND gate, one or more NAND gates can be used to replace an ________.

Accepted Answer

AND gate

Answer

OR gate