A multiplexer routes one selected input to what?
A Many inputs
B Clock source
C Single output
D Power rail
Answer: C. Single output. A mux selects one of multiple inputs using select bits.
A demultiplexer routes one input to what?
A All inputs
B Clock source
C Selected output
D Power rail
Answer: C. Selected output. A demux directs an input signal to one selected output.
A decoder activates an output based on what?
A Clock frequency
B Data bus width
C Supply voltage
D Input code
Answer: D. Input code. A decoder maps an input code to a corresponding output line.
A priority encoder resolves multiple active inputs by what?
A Highest priority
B Random selection
C Lowest voltage
D Clock order only
Answer: A. Highest priority. A priority encoder returns the code for the highest-priority asserted input.
A parity generator adds a bit for what purpose?
A Address decoding
B Clock division
C Error detection
D Power regulation
Answer: C. Error detection. Parity bits enable simple detection of odd numbers of bit errors.
A magnitude comparator determines which input is what?
A More recent
B Greater or equal
C More stable
D More powerful
Answer: B. Greater or equal. A comparator determines whether binary values are equal or ordered.
A ripple-carry adder passes carry through what?
A Parallel independent paths
B Memory banks
C Successive stages
D Clock domains
Answer: C. Successive stages. Each full-adder stage passes carry to the next stage.
A carry-lookahead adder speeds addition by predicting what?
A Clock edges
B Memory addresses
C Parity bits
D Carry signals
Answer: D. Carry signals. Carry-lookahead logic computes carries without waiting for ripple propagation.
A subtractor can use two’s complement addition by complementing and what?
A Subtracting one
B Adding one
C Shifting right
D Clearing carry
Answer: B. Adding one. A−B can be computed as A plus the two’s complement of B.
An ALU performs arithmetic and what operations?
A Logical operations
B Optical sensing
C Memory refresh
D Clock generation only
Answer: A. Logical operations. An arithmetic logic unit performs arithmetic and bitwise logic.
A code converter maps one representation into what?
A A clock edge
B An analog sensor
C Power supply
D Another code
Answer: D. Another code. Code converters translate between encodings such as binary, Gray or BCD.
BCD encodes each decimal digit using how many bits?
A Three bits
B Four bits
C Seven bits
D Eight bits
Answer: B. Four bits. Each decimal digit is represented by a four-bit binary-coded decimal group.
A seven-segment decoder drives what display elements?
A Seven LED segments
B Eight data buses
C Four clock phases
D Two registers
Answer: A. Seven LED segments. The decoder maps a code to segment control signals.
A tri-state output can be logic zero, logic one or what?
A High impedance
B Oscillating voltage
C Negative current
D Analog ground
Answer: A. High impedance. Tri-state logic adds a high-impedance state for bus sharing.
A shared digital bus uses tri-state drivers to prevent what?
A Clock drift
B Address overflow
C Signal encoding
D Output contention
Answer: D. Output contention. Only one driver should actively drive a shared bus at a time.
Rise time measures transition from low to what?
A High level
B High to low only
C Reset to clock
D Input to memory
Answer: A. High level. Rise time characterizes low-to-high signal transition duration.
Fall time measures transition from high to what?
A Low to high only
B Low level
C Clock to reset
D Memory to input
Answer: B. Low level. Fall time characterizes high-to-low transition duration.
A logic hazard is a temporary incorrect what?
A Stored state
B Output glitch
C Clock source
D Power rail
Answer: B. Output glitch. Hazards are transient glitches caused by unequal propagation delays.
A magnitude comparator can produce equality and what result?
A Greater-than or less-than
B Carry-in
C Parity only
D Clock enable
Answer: A. Greater-than or less-than. Comparators can indicate A>B, A=B or A<B.
A full adder has how many binary inputs?
A One input
B Two inputs
C Three inputs
D Four inputs
Answer: C. Three inputs. It accepts two operand bits and a carry-in.
A carry output indicates what from binary addition?
A Equality
B Parity
C Overflow to next bit
D Clock state
Answer: C. Overflow to next bit. Carry represents a value passed into the next more significant bit.
A barrel shifter can shift a word by what?
A Only one position
B No positions
C A byte only
D Multiple bit positions
Answer: D. Multiple bit positions. A barrel shifter performs variable shifts in combinational hardware.
A priority encoder usually includes what output?
A Valid signal
B Analog voltage
C Clock divider
D Memory page
Answer: A. Valid signal. A valid output indicates that at least one request input is active.
A decoder with n inputs can select up to how many outputs?
A n outputs
B 2^n outputs
C n squared outputs
D 2n outputs
Answer: B. 2^n outputs. An n-to-2^n decoder has one output for each input code.
A 4-to-1 multiplexer needs how many select bits?
A One bit
B Three bits
C Four bits
D Two bits
Answer: D. Two bits. Two select bits encode one of four input choices.