Logic Gates Interview Question Answer - 1

1	Which are the three basic gates?
	AND, OR and NOT
2	Which are the two logic levels of any gate?
	Logic level Low and High OR True and False OR One and Zero
3	What is meaning of Positive logic and Negative logic?
	Positive logic It is a logic system in which the higher of the two voltage level represents logic 1 and lower of the two voltage level represents logic 0. Negative logic It is a logic system in which the higher of the two voltage level represents logic 0 and lower of the two voltage level represents logic 1.
4	Explain the term : Logic circuit
	Logic circuit The interconnection of various gates to perform various logic functions is called as logic circuit.
5	Which gate is known as all or nothing gate? Why?
	The AND gate is known as all or nothing gate because the output is 1 if and only if all its inputs are 1.
6	Which gate is known as any or all gate?
	The OR gate is known as any or all gate because the output is 1 even if one of its input is 1.
7	What is condition for high output of AND gate?
	All inputs must be high.
8	What is condition for high output of OR gate?
	Any of one input is high
9	Which gate is also known as inverter gate?
	NOT gate
10	Which gate has only one input?
	NOT gate
11	Which gate is known as universal gate? Why?
	Universal Gate The NAND and NOR gates are known as universal gate because any gates as well as complex logic circuit can be realized by the NAND and NOR gates.
12	What is meaning of the AOI circuit?
	AOI circuit A logic circuit which use three gates AND, OR and INVERT is called as AOI circuit.
13	What is meaning of the AO circuit?
	AO circuit A logic circuit which use only two gates AND and OR is called as AO circuit.
14	What is bubble OR gate?
	Bubble OR gate The OR gate with inverter input is called as bubble OR gate.
15	Why the NAND gate is called as active low OR gate?
	Active low OR gate The NAND gate is called as active low OR gate because the output is at high state even if any of its input is low.