Past TU exam questions for Digital Logic, organised chapter by chapter with solutions.
What is the 2's complement of \((10110100)_2\)?
Convert \((9F)_{16}\) to decimal.
What is 2's complement? Subtract \((10110)_2 - (01011)_2\) using 2's complement method.
Write the Boolean expression for an Ex-NOR gate.
What is a min-term? Give an example for three variables A, B, C.
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.
Minimize the following function using K-Map and Tabulation method respectively
\(F(A,B,C,D) = \Sigma m(0,1,4,5,8,9,11)\)
What is a Full Adder? Write its sum output expression.
What is the purpose of a multiplexer?
Define Half Adder and Full Adder. Design a Full Adder circuit with its truth table, Boolean expressions, and logic diagram.
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.
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).
What is the difference between a latch and a flip-flop?
Explain D flip flop with characteristics table, equation and logical circuit.
What is synchronous counter?
What is register?
What is a Ripple counter? State one disadvantage.
What is shift register? Explain different types of shift register.
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.
