Logic gates are devices that act as the building blocks for digital circuits, and perform basic logical functions by taking decisions through a combination of digital signals coming from the inputs. Logic gates operate on the concept of Boolean function with having two inputs and one output. There are two binary conditions, true or false where true represents 1 and false represents 0. There are different types of logic gates and based on the type of logical gate, the output varies due to variation in the logical operation.
Multiple Choice Questions
Which gate is known as the universal gate?

 NAND
 OR
 AND
 None
Answer. A. NAND gate.
This is so because using multiples of nand gates, any logical gate (AND, OR, NOT, NAND,NOR) can be created.
2. How does a logic gate function?

 Using the flow of electric current
 Spontaneously
 By using energy from a chemical reaction
 None of the above
Answer. A. Using the flow of electric current.
Logic gates work on the concept of getting two input electric current flows, comparing them and sending on another electrical output, depending on what it finds.
3. Which of the following is not a logic gate?

 AND
 OR
 IF
 NOT
Answer. C. IF is not a logic gate.
Different types of basic logic gates that are there include AND, OR, NOT. using these gates and making different combinations out of them, various other gates like NAND, NOR, etc are created but there is no such gate by the name of IF.
4. Which of the following are the arithmetic logic gates?

 XOR
 XNOR
 Both
 None
Answer. C. Both.
XOR and XNOR are termed as arithmetic gates because these gates are so connected that they carry out an arithmetic action and the output they give are the digits of the result.
5. What is the full form of DCDVS logic?

 Differential cascade voltage switch
 Differential cascade voltage static
 Differential complex voltage switch
 None
Answer. A. Differential cascade voltage switch is the expanded form of DCDVS logic.
6. Who was the inventor of the idea of logic gates?

 George Boole
 Bardeen
 Claude Shannon
 Kornard Zuse
Answer. A. George Boole, son of a shoemaker class family, born in Lincoln, England, was the inventor of the idea and concept of logic gates.
7. What is the one’s complement for the binary number 011001

 000111
 100110
 111001
 110001
Answer. B. 100110.
The one’s complement means that one has to swap all the 0’s and 1’s. So for the given number, swapping 0’s and 1’s would give the number designated as option b as the answer.
8. Expand TTL

 Transistortransducer logic
 Transistor transistor logic
 Transducertransistor logic
 None
Answer. B. Transistortransistor logic is the correct full form of TTL.
9. How many types of logic families exist?

 Two
 Six
 Four
 Seven
Answer. D. Seven.
There are seven types of logic families, namely, RTL, DTL, IIL, TTL, ECL, MOS, CMOS.
10. Which of the following signifies a NOT gate?

 1 (input) 0 (output)
 1,0 (input) 1 (output)
 0,0 (input) 0 (output)
 None
Answer. A. 1 (input) 0 (output).
NOT gate reverses the input,so if input is true (1), output will be false (0) therefore, a is the correct option.
11. What is the boolean operation performed by an OR gate?

 Equivalent of addition
 Equivalent of multiplication
 Equivalent of dificsin
 Equivalent of subtraction.
Answer. A. Equivalent of addition
An OR gate performs addition function, so that if any of the two inputs is 1, it will give the output also as 1.
12. Which of the following gates can function on a single input?

 NOT
 AND
 OR
 None
Answer.A. Not gate can function on a single input, and invert that input.
13. A NAND gate has —– inputs and —— outputs.

 High input and High output
 High input and low output
 Low input and low output
 Low input and high output
Answer. D. Low input and high output.
A NAND gate is a combination of NOT and AND gates, so it will convert two low inputs to high inputs first and then give an AND based output for the modified inputs.
14. What is the Truth Table?

 It is a table representing what output will one get for a given input.
 It is a table representing what input and output will be given by a given boolean operator.
 Both of these
 None of these
Answer. C. Both of these.
Truth table represents for a given logic gate, what output will a particular input give.
15. What will be the output of the given logic gate?
 NOR
 NAND
 AND
 OR
Answer. 2.NAND gate.
These are a combination of OR gates and thus will in totality function to first invert the input and then give the high value output.
16. What is the full form of ILL?

 Injection integrated circuit
 Integrated injection circuit
 Integrated integrated circuit
 None
Answer. B. Integrated Injection circuit.
17. Who first made use of truth tables?

 Charles Sanders Pierce
 Father of Pragmatism
 Irving Annelis
 Both a and b
Answer. D. Both a and b.
Charles Sanders Pierce is also called the father of pragmatism, who first made use of truth tables.
18. Which are the forms of complex logic gates?

 OAI
 AOI
 Both
 None
Answer. C. Both OAI (ORAND Invert) and AOI (ANDORInvert) are the forms of complex logic gates.
19. What combination is a NAND gate?

 NOT AND
 NOT OR
 NOT NOT
 None of these
Answer. A. NOT AND.
NAND is a combination of NOT + AND gates
20. XOR circuits can be constructed using

 OR gates only
 AND, OR gates
 AND, NOT gates
 AND, NOT and OR gates
Answer. D. AND, NOT and OR gates can be combined to get exclusiveOR gates.