EEE 120 Quiz 4 Requires Respondus LockDown Browser +
Webcam Q&A | Graded A+ | Fall Update 2026-2027
1. Which of the following best describes the primary purpose of a Karnaugh
map in digital logic design?
A) To calculate the propagation delay of a logic circuit
B) To graphically simplify Boolean expressions by grouping adjacent 1s or 0s
C) To determine the power consumption of a combinational circuit
D) To simulate the timing behavior of a sequential circuit
Correct Answer: To graphically simplify Boolean expressions by grouping adjacent
1s or 0s
Rationale: A Karnaugh map (K-map) is a visual tool used to simplify Boolean
expressions by grouping adjacent cells containing 1s (for SOP) or 0s (for POS) into
the largest possible power-of-two groups. This process eliminates redundant
variables and produces a minimized expression. It does not calculate propagation
delay, power consumption, or simulate timing behavior.
2. What is the primary function of a multiplexer (MUX) in a digital system?
A) To convert parallel data to serial data
B) To select one of several input signals and route it to a single output
C) To perform binary addition of two numbers
D) To store multiple bits of data permanently
Correct Answer: To select one of several input signals and route it to a single
output
Rationale: A multiplexer is a combinational circuit that selects one of 2^n data
inputs based on n select lines and routes the selected input to a single output. It is
commonly used for data routing and signal selection. It does not perform
addition, store data, or convert data formats.
3. According to the EEE 120 Quiz 4 topics, which of the following is a key
characteristic of a programmable read-only memory (PROM)?
,A) Both the inputs and outputs are fixed, and data can only be programmed once
B) Data can be erased with ultraviolet light and reprogrammed multiple times
C) It is a volatile memory that loses data when power is removed
D) It has a programmable AND array and a fixed OR array
Correct Answer: Both the inputs and outputs are fixed, and data can only be
programmed once
Rationale: A PROM is a type of read-only memory that is programmed once by
the user after manufacturing. The inputs (address lines) and outputs (data lines)
are fixed, and once programmed, the data cannot be changed. It is non-volatile
and does not have a programmable AND array.
4. Which finding is most consistent with a Mealy state machine compared to a
Moore state machine?
A) The output depends only on the current state
B) The output depends on both the current state and the current inputs
C) The state machine requires more states to implement the same function
D) The output changes only on the clock edge
Correct Answer: The output depends on both the current state and the current
inputs
Rationale: In a Mealy machine, the output is a function of the current state and
the current inputs. This allows the Mealy machine to respond immediately to
input changes and often requires fewer states than an equivalent Moore machine,
whose output depends only on the current state.
5. What is the primary purpose of a decoder in a digital circuit?
A) To select one of several inputs and route it to an output
B) To convert an n-bit binary input into one of 2^n unique output lines
C) To store data temporarily during computation
D) To perform arithmetic operations on binary numbers
Correct Answer: To convert an n-bit binary input into one of 2^n unique output
lines
,Rationale: A decoder takes an n-bit binary input and activates exactly one of its
2^n output lines based on the input value. It is the functional opposite of a
multiplexer. It does not store data, perform arithmetic, or select inputs.
6. Which of the following statements about a D flip-flop is true?
A) The output changes on both the rising and falling edges of the clock
B) The next state is determined solely by the D input at the active clock edge
C) The output toggles when both J and K inputs are high
D) The output is transparent and follows the input when the enable signal is high
Correct Answer: The next state is determined solely by the D input at the active
clock edge
Rationale: A D flip-flop captures the value of the D input at the active clock edge
and transfers it to the output. The next state equation is Q(next) = D. It is edge-
triggered, not transparent (that is a latch), and does not toggle like a JK flip-flop.
7. What is the primary function of a shift register in a digital system?
A) To count the number of clock pulses applied to a circuit
B) To shift data bits from one stage to the next in a serial or parallel manner
C) To perform addition and subtraction of binary numbers
D) To generate clock signals for a sequential circuit
Correct Answer: To shift data bits from one stage to the next in a serial or parallel
manner
Rationale: A shift register is a cascade of flip-flops that can shift data bits from one
stage to the next. It is commonly used for serial-to-parallel and parallel-to-serial
data conversion. It does not count pulses, perform arithmetic, or generate clocks.
8. Which of the following best describes a synchronous counter?
A) Flip-flops are clocked sequentially, causing a ripple effect
B) All flip-flops are clocked simultaneously by the same clock signal
C) It uses no flip-flops and relies solely on combinational logic
D) It can only count down, not up
Correct Answer: All flip-flops are clocked simultaneously by the same clock signal
, Rationale: In a synchronous counter, the clock input is connected to all flip-flops,
so they change state simultaneously on the active clock edge. This eliminates the
ripple delay and glitches associated with asynchronous counters. Synchronous
counters can count both up and down.
9. What is the primary purpose of a state transition table in sequential circuit
design?
A) To list the next state and output for every combination of current state and
input
B) To calculate the power consumption of a state machine
C) To determine the physical layout of a circuit board
D) To measure the propagation delay of flip-flops
Correct Answer: To list the next state and output for every combination of current
state and input
Rationale: A state transition table (also called a state table) is a tabular
representation of a state machine. It lists the next state and output for each
current state and input combination. It is a fundamental tool for designing and
analyzing sequential circuits.
10.Which of the following is a characteristic of a programmable logic array
(PLA)?
A) It has a fixed AND array and a programmable OR array
B) It has a programmable AND array and a programmable OR array
C) It has a programmable AND array and a fixed OR array
D) It has no programmable elements and is fixed at manufacture
Correct Answer: It has a programmable AND array and a programmable OR array
Rationale: A PLA has both a programmable AND array and a programmable OR
array, allowing it to implement complex sum-of-products expressions. A PAL has a
programmable AND array and a fixed OR array, while a PROM has a fixed AND
array and a programmable OR array.
11.What is the minimum number of flip-flops required to implement a state
machine with 37 states?
Webcam Q&A | Graded A+ | Fall Update 2026-2027
1. Which of the following best describes the primary purpose of a Karnaugh
map in digital logic design?
A) To calculate the propagation delay of a logic circuit
B) To graphically simplify Boolean expressions by grouping adjacent 1s or 0s
C) To determine the power consumption of a combinational circuit
D) To simulate the timing behavior of a sequential circuit
Correct Answer: To graphically simplify Boolean expressions by grouping adjacent
1s or 0s
Rationale: A Karnaugh map (K-map) is a visual tool used to simplify Boolean
expressions by grouping adjacent cells containing 1s (for SOP) or 0s (for POS) into
the largest possible power-of-two groups. This process eliminates redundant
variables and produces a minimized expression. It does not calculate propagation
delay, power consumption, or simulate timing behavior.
2. What is the primary function of a multiplexer (MUX) in a digital system?
A) To convert parallel data to serial data
B) To select one of several input signals and route it to a single output
C) To perform binary addition of two numbers
D) To store multiple bits of data permanently
Correct Answer: To select one of several input signals and route it to a single
output
Rationale: A multiplexer is a combinational circuit that selects one of 2^n data
inputs based on n select lines and routes the selected input to a single output. It is
commonly used for data routing and signal selection. It does not perform
addition, store data, or convert data formats.
3. According to the EEE 120 Quiz 4 topics, which of the following is a key
characteristic of a programmable read-only memory (PROM)?
,A) Both the inputs and outputs are fixed, and data can only be programmed once
B) Data can be erased with ultraviolet light and reprogrammed multiple times
C) It is a volatile memory that loses data when power is removed
D) It has a programmable AND array and a fixed OR array
Correct Answer: Both the inputs and outputs are fixed, and data can only be
programmed once
Rationale: A PROM is a type of read-only memory that is programmed once by
the user after manufacturing. The inputs (address lines) and outputs (data lines)
are fixed, and once programmed, the data cannot be changed. It is non-volatile
and does not have a programmable AND array.
4. Which finding is most consistent with a Mealy state machine compared to a
Moore state machine?
A) The output depends only on the current state
B) The output depends on both the current state and the current inputs
C) The state machine requires more states to implement the same function
D) The output changes only on the clock edge
Correct Answer: The output depends on both the current state and the current
inputs
Rationale: In a Mealy machine, the output is a function of the current state and
the current inputs. This allows the Mealy machine to respond immediately to
input changes and often requires fewer states than an equivalent Moore machine,
whose output depends only on the current state.
5. What is the primary purpose of a decoder in a digital circuit?
A) To select one of several inputs and route it to an output
B) To convert an n-bit binary input into one of 2^n unique output lines
C) To store data temporarily during computation
D) To perform arithmetic operations on binary numbers
Correct Answer: To convert an n-bit binary input into one of 2^n unique output
lines
,Rationale: A decoder takes an n-bit binary input and activates exactly one of its
2^n output lines based on the input value. It is the functional opposite of a
multiplexer. It does not store data, perform arithmetic, or select inputs.
6. Which of the following statements about a D flip-flop is true?
A) The output changes on both the rising and falling edges of the clock
B) The next state is determined solely by the D input at the active clock edge
C) The output toggles when both J and K inputs are high
D) The output is transparent and follows the input when the enable signal is high
Correct Answer: The next state is determined solely by the D input at the active
clock edge
Rationale: A D flip-flop captures the value of the D input at the active clock edge
and transfers it to the output. The next state equation is Q(next) = D. It is edge-
triggered, not transparent (that is a latch), and does not toggle like a JK flip-flop.
7. What is the primary function of a shift register in a digital system?
A) To count the number of clock pulses applied to a circuit
B) To shift data bits from one stage to the next in a serial or parallel manner
C) To perform addition and subtraction of binary numbers
D) To generate clock signals for a sequential circuit
Correct Answer: To shift data bits from one stage to the next in a serial or parallel
manner
Rationale: A shift register is a cascade of flip-flops that can shift data bits from one
stage to the next. It is commonly used for serial-to-parallel and parallel-to-serial
data conversion. It does not count pulses, perform arithmetic, or generate clocks.
8. Which of the following best describes a synchronous counter?
A) Flip-flops are clocked sequentially, causing a ripple effect
B) All flip-flops are clocked simultaneously by the same clock signal
C) It uses no flip-flops and relies solely on combinational logic
D) It can only count down, not up
Correct Answer: All flip-flops are clocked simultaneously by the same clock signal
, Rationale: In a synchronous counter, the clock input is connected to all flip-flops,
so they change state simultaneously on the active clock edge. This eliminates the
ripple delay and glitches associated with asynchronous counters. Synchronous
counters can count both up and down.
9. What is the primary purpose of a state transition table in sequential circuit
design?
A) To list the next state and output for every combination of current state and
input
B) To calculate the power consumption of a state machine
C) To determine the physical layout of a circuit board
D) To measure the propagation delay of flip-flops
Correct Answer: To list the next state and output for every combination of current
state and input
Rationale: A state transition table (also called a state table) is a tabular
representation of a state machine. It lists the next state and output for each
current state and input combination. It is a fundamental tool for designing and
analyzing sequential circuits.
10.Which of the following is a characteristic of a programmable logic array
(PLA)?
A) It has a fixed AND array and a programmable OR array
B) It has a programmable AND array and a programmable OR array
C) It has a programmable AND array and a fixed OR array
D) It has no programmable elements and is fixed at manufacture
Correct Answer: It has a programmable AND array and a programmable OR array
Rationale: A PLA has both a programmable AND array and a programmable OR
array, allowing it to implement complex sum-of-products expressions. A PAL has a
programmable AND array and a fixed OR array, while a PROM has a fixed AND
array and a programmable OR array.
11.What is the minimum number of flip-flops required to implement a state
machine with 37 states?
