The format used to present the logic output for the various combinations of logic inputs to a gate is called a(n):
Answer: C
Correct answer: truth table
A truth table is the standard tabulation of a gate's output for every combination of its inputs. A Boolean variable is a single symbol and a Boolean constant is 0 or 1.
Please log in or register to report this question.
Write the Boolean expression for an inverter logic gate with input C and output Y.
Answer: B
Correct answer: \( Y = \overline{C} \)
An inverter produces the complement of its input, which is written with an overbar.
Please log in or register to report this question.
A NAND gate output is LOW only if all the inputs are HIGH.
Answer: A
Correct answer: True
NAND is the complement of AND, and AND is 1 only when every input is 1. So the NAND output is LOW in exactly that one case.
Please log in or register to report this question.
If A is LOW or B is LOW or BOTH are LOW, then X is LOW. If A is HIGH and B is HIGH, then X is HIGH. These rules specify the operation of a(n) ________.
Answer: A
Correct answer: AND gate
The rules describe an output that is HIGH only when both inputs are HIGH and LOW in every other case, which is the AND function. An OR gate would be HIGH whenever either input was HIGH.
Please log in or register to report this question.
The Boolean expression for a 3-input OR gate is ________.
Answer: B
Correct answer: X = A + B + C
OR is written as a sum, so a three-input OR sums all three variables.
Please log in or register to report this question.
How many input combinations would a truth table have for a six-input AND gate?
Answer: C
Correct answer: 64
A truth table has \( 2^n \) rows for n inputs, so six inputs give \( 2^6 = 64 \).
Please log in or register to report this question.
A 2-input NOR gate is equivalent to a ________.
Answer: B
Correct answer: negative-AND gate
By De Morgan's law \( (A+B)' = A'B' \), so a NOR gate gives 1 exactly when both inputs are 0 - that is, it is an AND gate for active-low inputs. Redrawing it with bubbles on the inputs and none on the output makes the equivalence visible.
Please log in or register to report this question.
If a 3-input NOR gate has eight input possibilities, how many of those possibilities will result in a HIGH output?
Answer: A
Correct answer: 1
A NOR output is HIGH only when every input is LOW, and of the eight combinations of three inputs exactly one has all three at 0.
Please log in or register to report this question.
The basic logic gate whose output is the complement of the input is the:
Answer: C
Correct answer: inverter
The inverter, or NOT gate, outputs the complement of its single input. AND and OR combine several inputs, and a comparator compares two values.
Please log in or register to report this question.
A demultiplexer is used to
Answer: C
Correct answer: Both (a) & (b)
A demultiplexer routes one input to a selected output, and if the select lines are stepped through in turn while bits arrive one after another, the same circuit distributes a serial stream across parallel outputs. Selecting one of many inputs is the multiplexer, which is the reverse operation.
Please log in or register to report this question.
