PLTW Digital Electronics (DE) Exam Questions
and Correct Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant Download Pdf
1. What is the primary purpose of a digital logic circuit?
A. To amplify only analog signals
B. To process information using discrete logic states
C. To convert mechanical energy into electrical energy
D. To store only magnetic information
Answer: B. To process information using discrete logic states
Rationale: Digital logic circuits process information using discrete
states, commonly represented as binary 0 and 1. These states are used
to perform logical operations, make decisions, store information, and
control electronic systems.
2. Which number system is most commonly used in digital
electronics?
,A. Decimal
B. Octal
C. Binary
D. Roman numeral
Answer: C. Binary
Rationale: Binary is the fundamental number system of digital
electronics because digital circuits generally operate using two
distinguishable logic states. These states are represented as 0 and 1.
3. How many different values can be represented by one binary
digit?
A. 1
B. 2
C. 8
D. 10
Answer: B. 2
Rationale: A binary digit, or bit, can have one of two possible values: 0
or 1. This two-state characteristic is the foundation of binary digital
systems.
, 4. What is the decimal equivalent of the binary number 1010₂?
A. 8
B. 9
C. 10
D. 12
Answer: C. 10
Rationale: The binary number 1010₂ represents 1×8 + 0×4 + 1×2 + 0×1
= 10 in decimal. Each binary position represents a power of two.
5. What is the binary equivalent of decimal 15?
A. 1010
B. 1100
C. 1110
D. 1111
Answer: D. 1111
Rationale: Decimal 15 equals 8 + 4 + 2 + 1, so all four corresponding
binary positions are 1. Therefore, 15₁₀ = 1111₂.
, 6. Which logic gate produces a HIGH output only when all of its
inputs are HIGH?
A. OR
B. AND
C. NOT
D. XOR
Answer: B. AND
Rationale: An AND gate requires every input to be HIGH for its output
to be HIGH. If even one input is LOW, the output is LOW.
7. Which logic gate produces a HIGH output when at least one input
is HIGH?
A. AND
B. NAND
C. OR
D. XNOR
Answer: C. OR
Rationale: An OR gate produces a HIGH output whenever one or more
inputs are HIGH. Its output is LOW only when every input is LOW.
and Correct Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant Download Pdf
1. What is the primary purpose of a digital logic circuit?
A. To amplify only analog signals
B. To process information using discrete logic states
C. To convert mechanical energy into electrical energy
D. To store only magnetic information
Answer: B. To process information using discrete logic states
Rationale: Digital logic circuits process information using discrete
states, commonly represented as binary 0 and 1. These states are used
to perform logical operations, make decisions, store information, and
control electronic systems.
2. Which number system is most commonly used in digital
electronics?
,A. Decimal
B. Octal
C. Binary
D. Roman numeral
Answer: C. Binary
Rationale: Binary is the fundamental number system of digital
electronics because digital circuits generally operate using two
distinguishable logic states. These states are represented as 0 and 1.
3. How many different values can be represented by one binary
digit?
A. 1
B. 2
C. 8
D. 10
Answer: B. 2
Rationale: A binary digit, or bit, can have one of two possible values: 0
or 1. This two-state characteristic is the foundation of binary digital
systems.
, 4. What is the decimal equivalent of the binary number 1010₂?
A. 8
B. 9
C. 10
D. 12
Answer: C. 10
Rationale: The binary number 1010₂ represents 1×8 + 0×4 + 1×2 + 0×1
= 10 in decimal. Each binary position represents a power of two.
5. What is the binary equivalent of decimal 15?
A. 1010
B. 1100
C. 1110
D. 1111
Answer: D. 1111
Rationale: Decimal 15 equals 8 + 4 + 2 + 1, so all four corresponding
binary positions are 1. Therefore, 15₁₀ = 1111₂.
, 6. Which logic gate produces a HIGH output only when all of its
inputs are HIGH?
A. OR
B. AND
C. NOT
D. XOR
Answer: B. AND
Rationale: An AND gate requires every input to be HIGH for its output
to be HIGH. If even one input is LOW, the output is LOW.
7. Which logic gate produces a HIGH output when at least one input
is HIGH?
A. AND
B. NAND
C. OR
D. XNOR
Answer: C. OR
Rationale: An OR gate produces a HIGH output whenever one or more
inputs are HIGH. Its output is LOW only when every input is LOW.
