BCA Digital Logic

bcasemester 1

This course familiarizes student with fundamentals of digital logic system

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Chapter Wise Notes Question Banks Syllabus Chapter Wise Questions Viva Practical

Faculty of Humanities and Social Sciences

2026

Bachelor of Computer Application

Digital Logic

BCA103

Full Marks: 60

Pass Marks: 24

Candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicate full marks.

"Group A (Very Short Question)"

Attempt all the questions.

[10×1 = 10]

What is the 2's complement of \((10110100)_2\)?

Convert \((9F)_{16}\) to decimal.

What is the difference between a latch and a flip-flop?

Write the Boolean expression for an Ex-NOR gate.

What is a min-term? Give an example for three variables A, B, C.

What is synchronous counter?

What is a Full Adder? Write its sum output expression.

What is the purpose of a multiplexer?

What is register?

What is a Ripple counter? State one disadvantage.

"Group B"

Attempt any SIX questions.

[6×5 =30]

What is 2's complement? Subtract \((10110)_2 - (01011)_2\) using 2's complement method.

Define Half Adder and Full Adder. Design a Full Adder circuit with its truth table, Boolean expressions, and logic diagram.

Explain D flip flop with characteristics table, equation and logical circuit.

Design full adder with truth table logical expression and logical circuit.

What is a Decoder? Explain a 2:4 Decoder with its block diagram, truth table, and logic circuit.

Prove De Morgan's second theorem \((A \cdot B)' = A' + B'\) using a truth table. Also realize a basic AND gate using NAND gates only.

What is shift register? Explain different types of shift register.

"Group C"

Attempt any TWO questions.

[2 × 10 = 20]

Minimize the following function using K-Map and Tabulation method respectively

\(F(A,B,C,D) = \Sigma m(0,1,4,5,8,9,11)\)

Design a 3-bit synchronous up counter using T flip-flops. Show the state diagram, state table, excitation table, Boolean expressions for inputs, and the complete logic diagram.

Design a combinational circuit with three inputs (X, Y, Z) and three outputs (A, B, C). When the binary input (X, Y, Z) is 0, 1, 2 or 3, the binary output is one greater than the input. When the binary input is 4, 5, 6 or 7, the binary output is one less than the input. Write the Truth Table for the inputs and outputs. Simplify the resulting expressions for A, B and C outputs (use algebra or maps).