ELEX 04

The binary numbers A = 1100 and B = 1001 are applied to the inputs of a comparator. What are the output levels?

• 
  A > B = 1, A < B = 0, A < B = 1

• 
  A > B = 0, A < B = 1, A = B = 0

• 
  A > B = 1, A < B = 0, A = B = 0

• 
  A > B = 0, A < B = 1, A = B = 1

A logic probe is placed on the output of a gate and the display indicator is dim. A pulser is used on each of the input terminals, but the output indication does not change. What is wrong?

• The output of the gate appears to be open

• 
  The dim indication on the logic probe indicates that the supply voltage is probably low

• 
  The dim indication is a result of a bad ground connection on the logic probe

• The gate may be a tristate device

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?

• 
  ₄₃₂₁ = 0111, C_out = 0

• ₄₃₂₁ = 1111, C_out = 1

• 
  ₄₃₂₁ = 1011, C_out = 1

• 
  ₄₃₂₁ = 1100, C_out = 1

Each "1" entry in a K-map square represents

• 
  a HIGH for each input truth table condition that produces a HIGH output

• 
  a HIGH output on the truth table for all LOW input combinations

• 
  a LOW output for all possible HIGH input conditions

• a DON'T CARE condition for all possible input truth table combinations

Looping on a K-map always results in the elimination of

• variables within the loop that appear only in their complemented form

• 
  variables that remain unchanged within the loop

• 
  variables within the loop that appear in both complemented and uncomplemented form

• 
  variables within the loop that appear only in their uncomplemented form

What will a design engineer do after he/she is satisfied that the design will work?

• 
  Put it in a flow chart

• Program a chip and test it

• 
  Give the design to a technician to verify the design

• 
  Perform a vector test

Based on the indications of probe A in the figure given below, what is wrong, if anything, with the circuit?

• 
  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

• 
  The output appears to be shorted to V_cc, but is being pulsed by the pulser

• The output appears to be LOW, but is being pulsed by the pulser

• Nothing appears to be wrong at that point

What is the indication of a short on the input of a load gate?

• Only the output of the defective gate is affected

• 
  There is a signal loss to all gates on the node.
  There is a signal loss to all gates on the node

• The affected node will be stuck in the LOW state

• 
  There is a signal loss to all gates on the node, and the affected node will be stuck in the LOW state

In HDL, LITERALS is/are

• 
  digital systems

• 
  scalars

• binary coded decimals

• 
  a numbering system

Which of the following expressions is in the sum-of-products form?

• 
  (A + B)(C + D)

• (AB)(CD)

• AB(CD)

• 
  AB + CD