8. Which of the following occurs when the enable input to a 3-line to 8- line decoder goes low (i.e. E=0)? Assume outputs of the decoder are active-low.

  1. All outputs go low(0)
  2. All outputs go high(1)
  3. The outputs go to a random pattern of 0's and 1's
  4. Power to the decoder chip is lost
  5. None of the above

2 is CORRECT. Since there is no bubble in front of E, we must assume that the Enable input is active-high. Thus E = 0 in this case means the decoder is disabled (turned off), and therefore, all outputs will go high. Also from question 7, Yi = (mi*E)' = 1 when E = 0 for all i.

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