# MCQs on Digital Electronics

##### Page 23 of 35. Go to page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
01․ The X-OR and X-NOR gates can have how many inputs?
2
1
4
any number

X-OR and X-NOR gates are available with two inputs only. In X-OR gate output is ‘1’ when number of 1’s at the input is odd number. Hence it is known as odd number of 1’s detector. In X-NOR gate output is ‘1’ when number of 1’s at the input is even number. Hence it is known as even number of 1’s detector.

02․ The logic expression AB can be implemented by giving the inputs A and B to a two-input
NOR gate
NAND gate
X-OR gate
X-NOR gate

The expression AB can be obtained by AND gate. Therefore AND gate simply can be obtaind by two NAND gates.

03․ The logic expression A + B can be implemented by giving inputs A and B to a two-input
NOR gate
NAND gate
X-OR gate
X-NOR gate

The expression A + B can be obtained by OR gate. Therefore OR gate simply can be obtain by two NOR gates.

04․ Which of the following is known as a mod-2 adder?
X-OR gate
X-NOR gate
NAND gate
NOR gate

The output of mod-2 adder or half adder is A ⊕ B. Therefore, the output is X-OR gate.

05․ What is the minimum number of two-input NAND gates used to perform the function of 2-input OR gate?
one
two
three
four

NAND and NOR gates are universal gates. By using of these gates we can realize any gate. T the minimum number of two-input NAND gates used to perform the function of 2-input OR gate are 3.

06․ NOT gates are to be added to the inputs of which gate to convert it to a NAND gate?
OR
AND
NOT
X-OR

The NOT gates are to be added to the inputs of OR gate, it will give the NAND gate output. Because, bubbled OR gate will acts as a NAND gate.

07․ NOT gates are to be added to the inputs of which gate to convert it to a NOR gate?
OR
AND
NAND
X-NOR

The NOT gates are to be added to the inputs of AND gate, it will give the NOR gate output. Because, bubbled AND gate will acts as a NOR gate.

08․ What logic function is produced by adding inverters to the inputs of an AND gate?
OR
NOR
NAND
X-OR

The NOT gates are to be added to the inputs of AND gate, it will give the NOR gate output. Because, bubbled AND gate will acts as a NOR gate.

09․ What logic function is produced by adding inverters to the inputs of an OR gate?
NOR
NAND
AND
X-NOR

The NOT gates are to be added to the inputs of OR gate, it will give the NAND gate output. Because, bubbled OR gate will acts as a NAND gate.

10․ What logic function is produced by adding an inverter to each input and output of an AND gate?
NOR
NAND
X-OR
OR

The NOT gates are to be added to the inputs of AND gate, it will give the NOR gate output. Because, bubbled AND gate will acts as a NOR gate. If we add another inverter at output side, it will give the OR gate output.

<<<2122232425>>>