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Home ‣ Digital Electronics ‣ Combinational Logic Circuits Comments
  • Question

  • A decoder can be used as a demultiplexer by ________.


  • Options
  • A. tying all enable pins LOW
  • B. tying all data-select lines LOW
  • C. tying all data-select lines HIGH
  • D. using the input lines for data selection and an enable line for data input

  • Correct Answer
  • using the input lines for data selection and an enable line for data input 

    • Combinational Logic Circuits problems

    Search Results

    • 1. A 74HC147 priority encoder has ten active-LOW inputs and four active-LOW outputs. What would be the state of the four outputs if inputs 4 and 5 are LOW and all other inputs are HIGH?

    • Options
    • A.
    • B.
    • C.
    • D.
      • Discuss
    • 2. Which of the following expressions is in the product-of-sums form?

    • Options
    • A. (A + B)(C + D)
    • B. (AB)(CD)
    • C. AB(CD)
    • D. AB + CD
      • Discuss
    • 3. How many 3-line-to-8-line decoders are required for a 1-of-32 decoder?

    • Options
    • A. 1
    • B. 2
    • C. 4
    • D. 8
      • Discuss
    • 4. The device shown here is most likely a ________.


    • Options
    • A. comparator
    • B. multiplexer
    • C. demultiplexer
    • D. parity generator
      • Discuss
    • 5. Based on the indications of probe A in the figure given below, what is wrong, if anything, with the circuit?


    • Options
    • A. The logic probe is unable to determine the state of the circuit at that point and is blinking to alert the technician to the problem.
    • B. The output appears to be shorted to Vcc, but is being pulsed by the pulser.
    • C. The output appears to be LOW, but is being pulsed by the pulser.
    • D. Nothing appears to be wrong at that point.
      • Discuss
    • 6. Which of the following combinations of logic gates can decode binary 1101?

    • Options
    • A. One 4-input AND gate
    • B. One 4-input AND gate, one OR gate
    • C. One 4-input NAND gate, one inverter
    • D. One 4-input AND gate, one inverter
      • Discuss
    • 7. An output gate is connected to four input gates; the circuit does not function. Preliminary tests with the DMM indicate that the power is applied; scope tests show that the primary input gate has a pulsing signal, while the interconnecting node has no signal. The four load gates are all on different ICs. Which instrument will best help isolate the problem?

    • Options
    • A. Current tracer
    • B. Logic probe
    • C. Oscilloscope
    • D. Logic analyzer
      • Discuss
    • 8. A full-adder has a Cin = 0. What are the sum (∑) and the carry (Cout) when A = 1 and B = 1?

    • Options
    • A. ∑ = 0, Cout = 0
    • B. ∑ = 0, Cout = 1
    • C. ∑ = 1, Cout = 0
    • D. ∑ = 1, Cout = 1
      • Discuss
    • 9. Two 4-bit binary numbers (1011 and 1111) are applied to a 4-bit parallel adder. The carry input is 1. What are the values for the sum and carry output?

    • Options
    • A. ∑4∑3∑2∑1 = 0111, Cout = 0
    • B. ∑4∑3∑2∑1 = 1111, Cout = 1
    • C. ∑4∑3∑2∑1 = 1011, Cout = 1
    • D. ∑4∑3∑2∑1 = 1100, Cout = 1
      • Discuss
    • 10. The device shown here is most likely a ________.


    • Options
    • A. comparator
    • B. multiplexer
    • C. demultiplexer
    • D. parity generator
      • Discuss

    Comments

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    Nadra
    Its very good
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