Digital Electronics - Practice Test

[#121] Following is the K-map of a Boolean function of five variables P, Q, R, S and X. The minimum sum-of-product (SOP) expression for the function is

(A) $$overline { ext{P}} overline { ext{Q}} { ext{S}}overline { ext{X}} + overline { ext{P}} overline { ext{Q}} { ext{S}}overline { ext{X}} + { ext{Q}}overline { ext{R}} overline { ext{S}} { ext{X}} + { ext{QR}}overline { ext{S}} { ext{X}}$$

(B) $$overline { ext{Q}} { ext{S}}overline { ext{X}} + { ext{Q}}overline { ext{S}} { ext{X}}$$

(C) $$overline { ext{Q}} { ext{SX}} + { ext{Q}}overline { ext{S}} overline { ext{X}} $$

(D) $$overline { ext{Q}} { ext{S}} + { ext{Q}}overline { ext{S}} $$

Correct Answer

(B) $$overline { ext{Q}} { ext{S}}overline { ext{X}} + { ext{Q}}overline { ext{S}} { ext{X}}$$

[#122] Y = A ⊕ B ⊕ A, where ⊕ represents XOR, is equal to:

(A) B

(B) AB

(C) $$overline { ext{A}} $$

(D) A

Correct Answer

(A) B

[#123] Match List-I with List-II and select the correct answer using the options given below the lists List-I List-II a. 45 1. 10110100 b. 90 2. 11010010 c. 180 3. 01011010 d. 210 4. 00101101 5. 10101000

(A) a-3, b-4, c-5, d-2

(B) a-4, b-3, c-1, d-2

(C) a-4, b-3, c-5, d-2

(D) a-3, b-4, c-2, d-1

Correct Answer

(B) a-4, b-3, c-1, d-2

[#124] A 4-bit R/2R digital-to-analog (DAC) converter has a reference of 5 volts. What is the analog output for the input code 0101?

(A) 0.3125 V

(B) 3.125 V

(C) 0.78125 V

(D) None of the above options

Correct Answer

(B) 3.125 V

[#125] An expression $${ ext{f}} = overline {overline {{ ext{AB}}} + overline { ext{A}} + { ext{AB}}} $$ xa0 xa0can be reduced to

(A) A

(B) B

(C) 0

(D) 1

Correct Answer

(C) 0

Digital Electronics - Study Mode

[#121] Following is the K-map of a Boolean function of five variables P, Q, R, S and X. The minimum sum-of-product (SOP) expression for the function is

Correct Answer

[#122] Y = A ⊕ B ⊕ A, where ⊕ represents XOR, is equal to:

Correct Answer

[#123] Match List-I with List-II and select the correct answer using the options given below the lists List-I List-II a. 45 1. 10110100 b. 90 2. 11010010 c. 180 3. 01011010 d. 210 4. 00101101 5. 10101000

Correct Answer

[#124] A 4-bit R/2R digital-to-analog (DAC) converter has a reference of 5 volts. What is the analog output for the input code 0101?

Correct Answer

[#125] An expression $${ ext{f}} = overline {overline {{ ext{AB}}} + overline { ext{A}} + { ext{AB}}} $$ xa0 xa0can be reduced to

Correct Answer