An unsigned n-bit number ranges from zero to what maximum?
A 2^n
B n squared
C 2n minus one
D 2^n minus one
Answer: D. 2^n minus one. An n-bit unsigned value has 2^n possible values from 0 through 2^n−1.
Two’s-complement n-bit signed range begins at what?
A −2^n
B −n
C −2^(n−1)
D Zero only
Answer: C. −2^(n−1). Two’s-complement signed range is −2^(n−1) through 2^(n−1)−1.
Hexadecimal digit A represents which decimal value?
A Eight
B Ten
C Twelve
D Sixteen
Answer: B. Ten. Hexadecimal A has decimal value ten.
A logical AND outputs one when what is true?
A Either input is one
B Both inputs are zero
C Inputs differ
D Both inputs are one
Answer: D. Both inputs are one. AND is true only when all input conditions are true.
A logical OR outputs one when what is true?
A Both inputs are zero
B Inputs are equal only
C Any input is one
D No input is one
Answer: C. Any input is one. OR is true when one or more inputs are true.
A NOT gate produces what output?
A Same input
B Sum of inputs
C Product of inputs
D Complemented input
Answer: D. Complemented input. NOT reverses a Boolean input value.
XOR outputs one when inputs are what?
A Different
B Both zero
C Both one
D Always equal
Answer: A. Different. Exclusive OR is true when its inputs differ.
De Morgan’s law transforms a negated AND into what?
A OR of negations
B AND of negations
C XOR of inputs
D Sum of bits
Answer: A. OR of negations. The complement of A AND B equals NOT A OR NOT B.
A half adder adds two bits and produces sum and what?
A Borrow only
B Clock
C Carry
D Overflow flag only
Answer: C. Carry. A half adder produces a sum bit and a carry bit.
A full adder also accepts which input?
A Carry-in
B Borrow-in
C Clock enable
D Parity bit
Answer: A. Carry-in. A full adder adds two bits plus an incoming carry.
A flip-flop stores how many bits?
A One bit
B One byte
C One word always
D One instruction
Answer: A. One bit. A basic flip-flop is a one-bit sequential storage element.
A combinational circuit output depends on what?
A Current inputs
B Past state only
C Clock history only
D Stored files
Answer: A. Current inputs. Combinational logic has no memory; its outputs depend on present inputs.
A sequential circuit output can depend on current input and what?
A Program size
B Previous state
C Bus width only
D Power supply color
Answer: B. Previous state. Sequential circuits include memory, so outputs depend on state history.
Overflow in signed addition occurs when what happens?
A Inputs are different
B Carry bit is zero
C Result exceeds signed range
D Values are unsigned
Answer: C. Result exceeds signed range. Signed overflow means the mathematical result cannot be represented in the fixed-width format.
Floating-point representation includes sign, exponent and what?
A Significand
B Parity
C Opcode
D Address bus
Answer: A. Significand. Floating-point formats represent values with a sign, exponent and significand.
A parity bit is added mainly to detect what?
A Arithmetic overflow
B Bit errors
C Memory address
D Instruction type
Answer: B. Bit errors. Parity provides a simple check for odd or even bit counts.
Hamming codes can support error correction by adding what?
A More data bytes only
B Redundant check bits
C A clock signal
D A processor core
Answer: B. Redundant check bits. Hamming codes use parity check bits to detect and correct certain errors.
An even-parity word contains an even number of what bits?
A One bits
B Zero bits
C Bytes
D Addresses
Answer: A. One bits. Even parity makes the total number of 1 bits even.
A truth table lists outputs for what?
A Memory addresses only
B Input combinations
C Clock frequencies
D Instruction cycles
Answer: B. Input combinations. Truth tables enumerate logical outputs for each possible input combination.
A multiplexer selects one of many inputs using what?
A Parity bits
B Clock gates
C Address decoders only
D Select lines
Answer: D. Select lines. Select lines determine which input is forwarded to the output.
A decoder converts an input code into what?
A A clock signal
B Analog voltage only
C One-of-many outputs
D A checksum
Answer: C. One-of-many outputs. A decoder activates an output corresponding to the input code.
A binary counter advances through what sequence?
A Decimal fractions
B Unicode characters
C Floating-point exponents
D Binary states
Answer: D. Binary states. A binary counter increments through a sequence of binary values.
A logic gate with inverted AND output is called what?
A NOR gate
B XOR gate
C Buffer
D NAND gate
Answer: D. NAND gate. A NAND gate outputs the complement of AND.
A logic gate with inverted OR output is called what?
A NAND gate
B XOR gate
C NOR gate
D Half adder
Answer: C. NOR gate. A NOR gate outputs the complement of OR.
A Boolean expression simplifies which circuit property?
A Clock frequency
B Logic implementation
C Memory capacity
D Cable length
Answer: B. Logic implementation. Boolean algebra can reduce gates and simplify digital logic.