Computer Hardware - ISC Class 12 Computer Science Questions with Answers
55 past-paper questions on Computer Hardware from ISC Class 12 Computer Science papers (2026-2017), newest first. Open one to see its answer.
- From the logic gate diagram given below, derive the Boolean expression for (1), (2) and S. Reduce the derived expression. 2026 · 3 marks · Derivation
- What is a decoder? Draw the logic gate diagram for decoding the binary numbers {0011, 0100, 0101, 0111, 1011, 1110} to… 2026 · 5 marks · Short answer
- Construct the logic gate diagram for a Full Adder using two Half Adders. 2026 · 3 marks · Drawing
- Draw the logic gate diagram for 2-input AND gate using NOR gates only. Show the expression at each step. 2026 · 2 marks · Drawing
- From the logic gate diagram given below, derive the Boolean expression for (1), (2) and Q. Reduce the derived expression. 2026 · 3 marks · Short answer
- Draw the logic gate diagram for a Full Adder. Write the Boolean expression for its SUM and CARRY. 2026 · 3 marks · Drawing
- How many maximum output lines would be there in a 4-input decoder? Draw the logic gate diagram for 8 : 1 multiplexer. State any… 2026 · 5 marks · Short answer
- Draw the logic gate diagram for 2-input OR gate using NAND gates only. Show the expression at each step. 2026 · 2 marks · Drawing
- Draw the logic gate diagram for an octal to binary encoder. State how multiplexer can be derived from a decoder. Mention one… 2025 · 5 marks · Drawing
- Following is the circuit diagram of a full adder. Redraw the circuit diagram by adding missing logic gates. 2025 · 2 marks · Drawing
- A 2 to 4 decoder contains 2 inputs denoted by A1 and A0 and 4 outputs denoted by D0, D1, D2, D3. Write the minterm… 2025 · 2 marks · Short answer
- Write the cardinal Product-of-Sum (POS) expression for the sum and carry of a full adder. 2025 · 2 marks · Short answer
- From the logic gate diagram given below: Derive Boolean expression for X(A, B, C) and draw the truth table. Write the canonical… 2025 · 5 marks · Long answer
- Study the logic gate diagram given below and answer the questions that follow: What will be the output of the above gate when… 2025 · 2 marks · One word
- Draw the logic circuit diagram for the simplified form of the following expression: $AB'C' + AB'C + ABC$ The circuit diagram… 2025 · 2 marks · Drawing
- A full adder needs five gates and those are 3 AND gates, 1 OR gate and 1 XOR gate. When a full adder is constructed using 2 half… 2025 · 1 mark · Short answer
- What is an encoder? Draw the logic gate diagram for an octal to binary encoder. State one application of a decoder. 2025 · 5 marks · Drawing
- Answer the following questions related to the below image: What is the output of the above gate if input $A = 0$, $B = 1$? 2025 · 1 mark · One word
- Draw the logic circuit to decode the following binary number (0001, 0101, 0111, 1000, 1010, 1100, 1110, 1111) to its hexadecimal… 2025 · 5 marks · Drawing
- Answer the following questions related to the below image: What are the values of the inputs if output = 1? 2025 · 1 mark · One word
- How is a 2 to 4 decoder related to 4:1 multiplexer? 2024 · 2 marks · Short answer
- State any one application each of half adder and full adder. 2024 · 1 mark · Short answer
- Draw the logic circuit to encode the following Hexadecimal number (1, 3, 5, 6, 9, A, C, E) to its binary equivalents. Also state… 2024 · 5 marks · Drawing
- When a sequence of OR, NOT, NOR are connected in series, the logic gate obtained is: 2024 · 1 mark · MCQ
- Draw the logic gate diagram for 2-input OR gate using NAND gates only. Show the expression at each step. 2024 · 3 marks · Drawing
- How is a decoder different from a multiplexer? Draw the logic circuit for 3:8 decoder (Octal decoder). Which multiplexer can be… 2024 · 5 marks · Drawing
- What is a half adder? Draw the logic circuit for the SUM and CARRY expression of a half adder using only NAND gates. 2023 · 3 marks · Drawing
- Differentiate between half adder and full adder. Write the Boolean expression and draw the logic circuit diagram for the SUM and… 2023 · 3 marks · Drawing
- Name the basic gate that is equivalent to two NOR gates connected in series. 2023 · 1 mark · One word
- What is an encoder? How is it different from a decoder? Draw the logic circuit for a 4:1 multiplexer and explain its working. 2023 · 5 marks · Drawing
- What is a decoder? How is it different from a multiplexer? Draw the logic circuit for a 2 to 4 decoder and explain its working. 2023 · 5 marks · Drawing
- From the logic diagram given above, where A, B and C are inputs and F is the output, answer the following question: The… 2022 · 1 mark · MCQ
- NAND gate is formed by the combinations of: 2022 · 1 mark · MCQ
- The combinational circuit which adds two binary bits is: 2022 · 1 mark · MCQ
- From the logic diagram given above, where A, B and C are inputs and F is the output, answer the following question: The… 2022 · 1 mark · MCQ
- If the input in a decoder is $A'BC'D$, then the decimal equivalent output will be: 2022 · 2 marks · MCQ
- From the logic diagram given above, where A, B and C are inputs and F is the output, answer the following question: The final… 2022 · 1 mark · MCQ
- Encoders are used for: 2022 · 1 mark · MCQ
- Draw the truth table and derive an SOP expression for sum and carry for a full adder. Also, draw the logic circuit for the carry… 2020 · 3 marks · Drawing
- Draw the logic circuit diagram for an octal to binary encoder and explain its working when a particular digit is pressed. Also… 2020 · 5 marks · Drawing
- Draw the circuit of a two input XOR gate with the help of NOR gates. 2020 · 3 marks · Drawing
- Define Universal gates. Give one example and show how it works as an OR gate. 2020 · 2 marks · Short answer
- Draw the logic diagram and truth table to encode the decimal numbers (2, 3, 5, 7, 8) and briefly explain its working. 2020 · 5 marks · Drawing
- Draw the logic diagram of 4:1 Multiplexer. 2020 · 2 marks · Drawing
- Study the diagram given below and answer the questions that follow: Name the basic gate which is represented by the diagram. What… 2020 · 1 mark · Short answer
- How is a decoder different from a multiplexer? Write the truth table and draw the logic circuit diagram for a 3 to 8 decoder and… 2019 · 5 marks · Long answer
- What is a half adder? Write the truth table and derive an SOP expression for sum and carry for a half adder. 2019 · 3 marks · Derivation
- Name and draw the logic gate represented by the following truth table, where A and B are inputs and X is the output. A B X 0 0 0… 2019 · 1 mark · Drawing
- From the logic circuit diagram given below, derive the Boolean expression and simplify it to show that it represents a logic… 2019 · 3 marks · Drawing
- Using only NAND gates, draw the logic circuit diagram for $A' + B$. 2018 · 2 marks · Drawing
- What is an Encoder? Draw the Encoder circuit to convert A-F hexadecimal numbers to binary. State an application of a Multiplexer. 2018 · 5 marks · Drawing
- Differentiate between Half Adder and Full Adder. Draw the logic circuit diagram for a Full Adder. 2018 · 3 marks · Drawing
- What is a Multiplexer? How is it different from a decoder? Draw the circuit diagram for an 8:1 Multiplexer. 2017 · 5 marks · Drawing
- State the application of a Half Adder. Draw the truth table and circuit diagram for a Half Adder. 2017 · 3 marks · Drawing
- Draw the logic diagram and truth table for a 2 input XNOR gate. 2017 · 1 mark · Drawing
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