ECE249 Unit 3: Introduction to number system and logic gates - MCQ Practice | B. Tech. CSE

1 $Which of the following represents the decimal number in binary?$

A.

B.

C.

D.

2 $Convert the hexadecimal number to its decimal equivalent.$

A.

B.

C.

D.

3 $What is the decimal value of the binary number ?$

A.

B.

C.

D.

4 $Which of the following is an unweighted code?$

A.

8421 Code

B.

BCD Code

C.

Excess-3 Code

D.

2421 Code

5 $Convert the binary number to Gray code.$

A.

B.

C.

D.

6 $The Gray code represents which binary number?$

A.

B.

C.

D.

7 $What is the BCD (8421) representation of decimal number ?$

A.

B.

C.

D.

8 $What is the Excess-3 code for the decimal number ?$

A.

B.

C.

D.

9 $The 2's complement of the binary number is:$

A.

B.

C.

D.

10 $In 8-bit 2's complement representation, what is the range of integers that can be represented?$

A.

-127 to +128

B.

-128 to +127

C.

0 to 255

D.

-256 to +255

11 $Perform the subtraction using 2's complement method.$

A.

B.

C.

D.

12 $Which logic gate is known as the 'Universal Gate'?$

A.

OR

B.

XOR

C.

NAND

D.

AND

13 $The output of an XOR gate is HIGH only when:$

A.

Both inputs are HIGH

B.

Both inputs are LOW

C.

The inputs are different

D.

The inputs are the same

14 $Which boolean law states that ?$

A.

De Morgan's Law

B.

Redundancy Law

C.

Distributive Law

D.

Absorption Law

15 $According to De Morgan's first theorem, is equal to:$

A.

B.

C.

D.

16 $A 4-variable K-Map contains how many cells?$

A.

16

B.

32

C.

8

D.

12

17 $In a K-Map, grouping 4 adjacent s (a quad) eliminates how many variables from the term?$

A.

1

B.

2

C.

3

D.

0

18 $The canonical sum of products (SOP) form consists of terms called:$

A.

Minterms

B.

Maxterms

C.

Sumterms

D.

Midterms

19 $Convert the octal number to binary.$

A.

B.

C.

D.

20 $What is the 9's complement of the decimal number ?$

A.

B.

C.

D.

21 $The boolean expression simplifies to:$

A.

B.

C.

D.

22 $Which of the following codes is known as a self-complementing code?$

A.

Gray Code

B.

8421 BCD

C.

Excess-3

D.

Octal

23 $The simplified boolean expression for the K-Map grouping involving corners of a 4-variable map () is:$

A.

B.

C.

D.

24 $The symbol represents which form?$

A.

Canonical SOP

B.

Simplified SOP

C.

Standard POS

D.

Canonical POS

25 $In boolean algebra,$

A.

B.

C.

D.

26 $Which gate is equivalent to an AND gate followed by a NOT gate?$

A.

XOR

B.

XNOR

C.

NOR

D.

NAND

27 $What is the result of adding binary numbers ?$

A.

B.

C.

D.

28 $A digital circuit that produces a logic output when the input number of s is odd is:$

A.

XNOR gate

B.

AND gate

C.

XOR gate

D.

OR gate

29 $If and, what is the value of ?$

A.

B.

High Impedance

C.

D.

Indeterminate

30 $The dual of the boolean expression is:$

A.

B.

C.

D.

31 $In a 3-variable K-map, the cells and are considered:$

A.

Isolated

B.

Adjacent

C.

Opposite

D.

Diagonal

32 $Which of the following is equivalent to the Boolean function ?$

A.

B.

C.

D.

33 $Convert the binary fraction to decimal.$

A.

B.

C.

D.

34 $What is the radix of the octal number system?$

A.

10

B.

16

C.

2

D.

8

35 $The boolean expression is equivalent to:$

A.

B.

C.

D.

36 $To perform binary subtraction using 1's complement:$

A.

Add to 1's complement of . If carry generated, add 1 to sum.

B.

Subtract directly.

C.

Add to .

D.

Add to 1's complement of . If carry generated, ignore it.

37 $What is the minimum number of NAND gates required to implement an OR gate?$

A.

1

B.

2

C.

3

D.

4

38 $In K-Map simplification, 'Don't Care' conditions are represented by:$

A.

1

B.

Z

C.

X

D.

0

39 $The Gray code is often used in:$

A.

Shaft position encoders

B.

Floating point operations

C.

Error correction

D.

Arithmetic operations

40 $Which of the following corresponds to the Logic equation ?$

A.

NOR

B.

XNOR

C.

XOR

D.

NAND

41 $What is the 1's complement of ?$

A.

B.

C.

D.

42 $Convert decimal to Excess-3 code.$

A.

B.

C.

D.

43 $The distributive law applies to:$

A.

Only boolean algebra

B.

Neither

C.

Only ordinary algebra

D.

Both boolean and ordinary algebra

44 $If a 3-input NAND gate has inputs, the output is:$

A.

1

B.

0

C.

Undefined

D.

High Impedance

45 $The standard POS form of the expression corresponds to:$

A.

Product of Minterms

B.

Product of Maxterms

C.

Sum of Maxterms

D.

Sum of Minterms

46 $The binary code for Hexadecimal is:$

A.

B.

C.

D.

47 $Which theorem allows moving a bubble from the output of an AND gate to the inputs, changing the gate to OR?$

A.

De Morgan's Theorem

B.

Consensus Theorem

C.

Duality Theorem

D.

Superposition Theorem

48 $Overflow in 2's complement addition occurs when:$

A.

Adding two numbers of same sign yields a result of opposite sign

B.

Adding a positive and a negative number

C.

Always when carry out is 1

D.

Carry out occurs from MSB

49 $In a 4-variable K-Map, how are the rows and columns labeled?$

A.

Randomly

B.

Gray Code ()

C.

Binary Sequence ()

D.

Decimal Order

50 $The value of in boolean algebra is:$

A.

B.

C.

D.

Unit 3: Introduction to number system and logic gates - Practice Quiz

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