STLD QUESTION BANK

CLASS TEST - 2 

short questions: 

1. Define Karnaugh -map. draw 2,3 variable K-map with min terms and max terms 

2. Draw half-adder truth table & circuit 

 3. Draw half-subtractor truth table & circuit 

 4. What is an prime implicant & essential prime implicant? 

 5. Reduce the following expression using Karnaugh map F= B'A + A'B+AB 

6. Simplify the following to minimum number of literals. 

            (i)A ̅ B(D + C̅D) + B(A ̅ + ACD)                 ii) x̅y+ xy + x̅y 

7. Find the minimized SOP expression for F = Σ(1, 3, 5) & realize using NAND gates. 

 8. Simplify F(A, B, C) = Π(1, 3, 5) & realize using NOR gates.
Long questions: 

1. Design BCD TO GRAY code converter using K Map draw the complete circuit diagram. 

2. Design a 4 bit ADDER/SUBTRACTOR circuit with add/sub control Line 

3. Design full adder using NAND gate explain operation 

4. Implement function using by using only NOR gates f=(w,x,y,z) =∑(0,2,4,9,12,15)+ ∑d(6,7,8,9,11,15) 5. Design full subtractor using NAND gate explain operation 

6. Obtain the minimal expression by using K-MAP method.

            f( a,b,c,d,e) = ∑m(1,4,8,10,11,20,22,24,25,26) + ∑d(0,12,16,17) 

7. Design and implement a Look-Ahead carry Adder. 

8. Redraw the given circuit in figure after simplification  

 

MID-1 QUESTION BANK: 

UNIT-1: 

1. Illustrate the operation of two-input AND, OR, NOR, NAND, and XOR gates by drawing their logic symbols, truth tables, and corresponding Boolean expressions. 

2. Convert the given binary number 101101.101 into its equivalent decimal and hexadecimal representations. 

3. Calculate ( A - B) decimal number A=37.42 from B=49.69 by using 9’s complement and 10’s complement methods 

4. Determine the complements of the following Boolean expressions: 

(i) AB+A(B+C)+B’(B+D)                  (ii) A+B+A’B’C 

5. Calculate the product of the octal numbers (23)8 and (12)8, and verify the result by converting it into the decimal number system. 

6. Explain the standard (canonical) SOP and POS forms for a three-variable Boolean function with suitable examples. 

7. Realize XOR and XNOR gates using only NOR gates. Draw the corresponding logic circuits? 

8. Realize XOR and XNOR gates using only NAND gates. Draw the corresponding logic circuits and verify their operation using truth tables. 

9. Encode the decimal number (32.89)10 using 8421, 84-2-1, 2421, Excess-3, and Gray codes. 

10. Calculate the subtraction (569.5-745.3) using 7’s complement and 8’s complement methods. 

11. Explain the significance of the base (radix) of a number system and describe the (r)’s and ((r-1))’s complement methods with suitable examples. 

12. Determine and analyze the value of the base (x) for the following number-system equations: a) (211)x =(152)8 b) (292)10 = (1204)x 

13. Determine the complements of the following Boolean expressions: (i) (AB+A(B+C)+B'(B+D)) (ii) (A+B+A'B'C) 

14. Calculate the product of the binary numbers (1011)2 and (1110)2, and verify the result in the decimal number system. 

15. Convert the following Boolean function into its canonical SOP and POS forms:

 f(A,B,C,D) = ( AB + C) ( B + C'D ) 

16. Explain the different methods used to represent negative numbers in binary and illustrate the representation of signed numbers from (+7) to (-8). 

17. Explain the different methods used to represent negative numbers in the binary number system with suitable examples. 

18. Calculate ( A - B) of binary number A=(1001.101)2 from B=(1101.001)2 using both 1’s complement and 2’s complement methods. 

19. Realize NOT and OR gates using NAND and NOR gates. Draw the corresponding logic circuits? 20. Explain weighted and non-weighted binary codes and illustrate each type with suitable examples. 21. Convert the given Boolean function into its canonical SOP and POS forms: f= w y + x (w +y zl ) 

22. Calculate (49.69 - 37.42) using both 9’s complement and 10’s complement methods. 

23. Encode the specified decimal numbers using the 6,3,1,-1 weighted code and determine whether the code is self-complementing. Justify your conclusion. 

24. Calculate the product of the hexadecimal numbers ( CA )H and ( E8 )H, and verify the result by converting it into the decimal number system. 

UNIT-2: 

1. Design and develop a BCD-to-Gray code converter using the K-map method and construct its complete logic circuit. 

2. Design and develop a BCD-to-Excess-3 code converter using the K-map method and construct its complete logic circuit. 

3. Analyze and simplify the following Boolean function using the K-map method and realize the simplified function using NOR gates: f(a,b,c,d,e) = πM(0,2,3,10,12,16,17,18,21,26,27)+ πd(11,13,19,20) 

4. Analyze and simplify the given Boolean function using the K-map method by considering the specified don’t-care conditions, and realize the simplified function using NAND gates: F(A, B, C, D) =∑m (4, 5, 7, 12, 13, 14) ∑d (1, 9, 11, 15) 

5. Explain the operation of a Look-Ahead Carry Adder and illustrate its working using a suitable circuit diagram and Boolean expressions. 

6. Analyze the given logic circuit using K-map or Boolean algebra, simplify the corresponding Boolean expressions, and redraw the simplified circuit. 

 7. Analyze the given logic circuit using K-map or Boolean algebra, derive and simplify the expressions for G1, G2, G3, G4, G5, G6 and X, and redraw the simplified circuit ? 

 8. Analyze and simplify the following Boolean function using the K-map method and realize the simplified function using NAND gates: f( a,b,c,d,e) = ∑m(1,4,8,10,11,20,22,24,25,26) + ∑d(0,12,16,17) 

9. Design and construct a full adder using two half adders. Realize the resulting circuit using NOR gates and develop its functional table. 

10. Analyze the given logic circuit using K-map or Boolean algebra, derive and simplify the expressions for X1, X2, X3, X4 & F, and redraw the simplified circuit ? 

 11. Analyze and simplify the following Boolean function using the K-map method and realize the simplified function using NOR gates: f(a,b,c,d,e) = πM(0,2,3,10,12,16,17,18,21,26,27) + dM(11,13,19,20) 

12. Design and construct a full subtractor using two half subtractors. Realize the resulting circuit using NAND gates and develop its functional table. 

13. Design and develop a Gray-to-binary code converter using the K-map method and construct its complete logic circuit.