CET Digital Logic & Microprocessors 2 — Questions and Answers
Question 1: In a microprocessor-controlled euthanasia chamber, a sensor outputs a HIGH signal when CO2 concentration exceeds 70%. Which logic gate produces a HIGH output only when BOTH the concentration sensor AND the door-closed sensor are HIGH?
- OR gate
- AND gate (Correct answer)
- NOT gate
- XOR gate
Correct answer: AND gate
An AND gate outputs HIGH only when all inputs are simultaneously HIGH, making it ideal for safety interlocks requiring multiple conditions to be met.
Question 2: A euthanasia equipment controller uses an 8-bit binary counter to track cycle duration. What is the maximum decimal count value this counter can represent?
- 128
- 256
- 255 (Correct answer)
- 512
Correct answer: 255
An 8-bit counter can represent values from 0 to 255 (2^8 - 1 = 255), giving 256 total states.
Question 3: Which number system uses only the digits 0 and 1 and is the native language of digital microprocessors in euthanasia equipment controllers?
- Octal
- Hexadecimal
- Decimal
- Binary (Correct answer)
Correct answer: Binary
Binary (base-2) is the fundamental number system of all digital microprocessors because electronic components naturally represent two states: on (1) and off (0).
Question 4: A gas flow controller in a euthanasia system uses a truth table with inputs A (flow valve) and B (pressure OK). The output is HIGH only when A=1 and B=0, OR when A=0 and B=1. Which gate implements this logic?
- NAND gate
- NOR gate
- XOR gate (Correct answer)
- XNOR gate
Correct answer: XOR gate
An XOR (exclusive OR) gate outputs HIGH only when inputs differ, matching the condition A=1,B=0 or A=0,B=1.
Question 5: In a microprocessor-based euthanasia system, the program counter (PC) register serves what primary function?
- Stores the current sensor reading
- Holds the address of the next instruction to execute (Correct answer)
- Counts the number of completed euthanasia cycles
- Stores the result of the last arithmetic operation
Correct answer: Holds the address of the next instruction to execute
The program counter always holds the memory address of the next instruction the CPU will fetch and execute, controlling program flow.
Question 6: A euthanasia equipment display shows the hexadecimal value 0xFF. What is the decimal equivalent?
- 240
- 254
- 255 (Correct answer)
- 256
Correct answer: 255
0xFF in hexadecimal equals 15×16 + 15 = 240 + 15 = 255 in decimal.
Question 7: Which type of memory in a euthanasia controller retains its stored program and calibration data even when power is removed?
- RAM (Random Access Memory)
- Cache memory
- ROM/Flash memory (Correct answer)
- Register file
Correct answer: ROM/Flash memory
ROM and Flash memory are non-volatile, retaining data without power, making them suitable for storing firmware and calibration settings in euthanasia equipment.
CET Digital Logic & Microprocessors 2
In a microprocessor-controlled euthanasia chamber, a sensor outputs a HIGH signal when CO2 concentration exceeds 70%.
Which logic gate produces a HIGH output only when BOTH the concentration sensor AND the door-closed sensor are HIGH?