Digital Logic Design – 300 MCQs
Course-Aligned Multiple Choice Questions for Exam Preparation
Number Systems, Gates, Boolean Algebra, K-Maps, Combinational and Sequential Circuits
The radix of the binary number system is:
The radix of the octal number system is:
The radix of the hexadecimal number system is:
Decimal 13 is equal to which binary number?
Binary 1010 is equal to decimal:
Binary 1111 is equal to decimal:
Hexadecimal A is equal to decimal:
Hexadecimal F is equal to decimal:
Octal 17 is equal to decimal:
The decimal number 255 in hexadecimal is:
A binary digit is called a:
A nibble contains:
A byte contains:
BCD stands for:
Which of the following is a valid BCD code for decimal 9?
The 1's complement of 101100 is:
The 2's complement of 101100 is:
The 1's complement operation simply:
The 2's complement of 0000 is:
In signed 2's complement, the MSB usually represents the:
Adding binary 1 + 1 gives:
Adding binary 1 + 1 + 1 gives:
The carry generated by 1 + 1 in binary is:
Gray code is useful because adjacent numbers:
Which code is non-weighted?
ASCII is primarily used to represent:
The maximum unsigned decimal value of 4 bits is:
The range of an unsigned 8-bit number is:
The binary equivalent of decimal 32 is:
The hexadecimal equivalent of binary 1110 is:
The octal equivalent of binary 111111 is:
The decimal equivalent of binary 100000 is:
Overflow in binary addition occurs when:
The signed 8-bit 2's complement range is:
To convert a hexadecimal number to binary, each hex digit is replaced by:
To convert an octal number to binary, each octal digit is replaced by:
Which representation is commonly used for error-free mechanical position sensing?
Excess-3 code is obtained by adding ____ to each decimal digit in BCD.
An AND gate produces logic 1 only when:
An OR gate produces logic 0 only when:
A NOT gate is also called an:
A NAND gate is an AND gate followed by a:
A NOR gate is an OR gate followed by a:
The XOR gate output is 1 when its inputs are:
The XNOR gate output is 1 when its inputs are:
Which gate is known as a universal gate?
Which pair of gates are universal gates?
The Boolean expression for an AND operation is usually written with:
The Boolean expression for an OR operation is usually written with:
The complement of A is commonly written as:
According to the identity law, A + 0 equals:
According to the identity law, A·1 equals:
According to the null law, A + 1 equals:
According to the null law, A·0 equals:
According to the idempotent law, A + A equals:
According to the idempotent law, A·A equals:
According to the complement law, A + A' equals:
According to the complement law, A·A' equals:
The involution law states that (A')' equals:
The commutative law for OR is:
The commutative law for AND is:
The associative law for OR is:
The distributive law of AND over OR is:
De Morgan's theorem states that (AB)' equals:
De Morgan's theorem states that (A + B)' equals:
The absorption law A + AB simplifies to:
The absorption law A(A + B) simplifies to:
A buffer gate is used mainly to:
The output of a 2-input XOR gate for inputs 1 and 1 is:
The output of a 2-input XNOR gate for inputs 0 and 0 is:
The Boolean expression A + BC can be converted using distributive law to:
A truth table lists:
The number of rows in the truth table of a 3-variable function is:
A minterm is a product term that contains:
A maxterm is a sum term that contains:
The expression Y = A⊕B⊕Cin is commonly the sum output of a:
A Karnaugh map is primarily used to:
A 2-variable K-map contains:
A 3-variable K-map contains:
A 4-variable K-map contains:
Adjacent cells in a K-map differ in:
K-map adjacency follows:
In K-map grouping, valid group sizes are powers of:
Which of the following is a valid K-map group size?
The purpose of making the largest possible K-map groups is to:
A pair in a K-map eliminates:
A quad in a K-map eliminates:
An octet in a 4-variable K-map eliminates:
A group of 16 in a 4-variable K-map simplifies to:
K-map edges are considered adjacent because the map:
A don't-care condition may be used to:
The term essential prime implicant means:
Prime implicants are:
The Quine-McCluskey method is also called the:
The Quine-McCluskey method is especially useful for:
In the tabulation method, terms are first grouped by:
Two terms can be combined in Quine-McCluskey if they differ in:
The symbol '-' in Quine-McCluskey indicates:
Sum-of-products form is an OR of:
Product-of-sums form is an AND of:
A canonical SOP expression is formed from:
A canonical POS expression is formed from:
Boolean simplification aims to reduce:
The simplified expression usually produces the same:
In a K-map, overlapping groups are:
For POS minimization using a K-map, we group:
A singleton 1 in a K-map represents:
The minimum number of literals in an implicant occurs with:
K-maps are practical mainly up to about:
The main limitation of K-maps is that they become hard to use for:
A redundant group in K-map minimization is one that:
When minimizing a function, don't-care cells may be treated as:
The tabulation method gives a systematic way to find:
A combinational circuit's output depends on:
A half adder adds:
The outputs of a half adder are:
The sum output of a half adder is implemented using:
The carry output of a half adder is implemented using:
A full adder adds:
A full adder has how many inputs?
The carry-out of a full adder is 1 when:
A half subtractor provides:
A full subtractor has inputs A, B and:
An encoder converts:
A decoder converts:
A 2-to-4 decoder has:
The number of outputs of an n-to-2^n decoder is:
A priority encoder is different from a normal encoder because it:
A multiplexer selects:
A 4-to-1 multiplexer has:
A demultiplexer routes:
Which combinational block can implement Boolean functions by data selection?
A comparator is used to:
A magnitude comparator determines whether:
A code converter changes:
A BCD-to-7-segment decoder drives:
A parity generator is used for:
Even parity means the total number of 1s is:
A carry look-ahead adder is designed to:
Ripple carry adders are slower because carry:
The output of a decoder is usually:
An active-low output is asserted when it is:
A tri-state buffer can output:
High impedance state is commonly denoted by:
A bus is typically shared using:
A PLA stands for:
A ROM-based combinational design stores:
A combinational circuit has ____ memory.
Hazards in combinational logic are unwanted:
Static hazards are often reduced by adding:
A full adder can be built using:
A sequential circuit differs from a combinational circuit because it has:
The basic memory element in digital electronics is a:
An SR latch has inputs:
The forbidden condition in a NOR-based SR latch occurs when:
A gated latch is controlled by an:
A D latch eliminates the invalid SR condition by ensuring:
A flip-flop is generally:
A D flip-flop stores the value of D on the:
The characteristic equation of a D flip-flop is:
A T flip-flop toggles when T equals:
A T flip-flop holds its state when T equals:
The JK flip-flop removes the invalid state of the:
A JK flip-flop toggles when:
Asynchronous inputs in flip-flops usually include:
The preset input forces Q to:
The clear input forces Q to:
Level-triggered devices respond during:
Edge-triggered devices respond at:
Race-around problem is associated with:
The race-around problem can be reduced by using:
A master-slave flip-flop uses:
Setup time is the minimum time data must be stable ____ the active clock edge.
Hold time is the minimum time data must remain stable ____ the active clock edge.
Clock-to-Q delay is the time from:
A transparent latch means the output follows the input when:
A synchronous sequential circuit changes state based on:
The present state and input determine the:
A state table lists:
A state diagram represents:
The output of a Moore machine depends on:
The output of a Mealy machine depends on:
A Mealy machine often reacts:
State reduction aims to:
Equivalent states are states that:
State assignment means:
Sequential logic analysis often starts with:
The characteristic equation of a T flip-flop is:
The characteristic equation of a JK flip-flop is:
A counter is a sequential circuit that:
An asynchronous counter is also called a:
A synchronous counter clocks all flip-flops:
Ripple counters are simpler but have more:
A mod-8 counter requires how many flip-flops?
A mod-16 counter requires how many flip-flops?
The modulus of a counter is the:
A binary up-counter counts:
A down-counter counts:
An up/down counter can count:
A decade counter is a:
A truncated counter is one that:
Counter decoding is used to:
A ring counter is made from a shift register with:
A Johnson counter is also called a:
An n-bit ring counter has how many valid states?
An n-bit Johnson counter has how many valid states?
A shift register is used to:
A SISO register stands for:
A SIPO register stands for:
A PISO register stands for:
A PIPO register stands for:
Shifting left by one bit in unsigned binary is equivalent to:
Shifting right by one bit in unsigned binary is equivalent to:
A universal shift register can:
The serial output of a shift register is usually taken from:
A bidirectional shift register can shift:
Parallel load means:
A ring counter typically starts with:
A Johnson counter sequence length of a 4-bit design is:
In a ripple counter, the clock of each stage is driven by:
Synchronous counters are generally preferred for high speed because they:
The terminal count output usually indicates:
A load input on a counter is used to:
A ring counter is less hardware-efficient than a binary counter because it uses:
Frequency division can be achieved using:
A divide-by-2 circuit can be realized using a toggle flip-flop driven by:
RAM stands for:
ROM stands for:
SRAM stores data using:
DRAM stores data using:
DRAM needs periodic:
SRAM is generally ____ than DRAM.
ROM is mainly used for:
PROM can be programmed:
EPROM can be erased using:
EEPROM can be erased:
Flash memory is a type of:
A memory cell stores:
The number of address lines needed for 1024 locations is:
The number of data lines determines the memory:
MAR in a computer system typically stands for:
MDR or MBR is used to hold:
An address decoder in memory selects:
Read operation means:
Write operation means:
Volatile memory loses data when:
Non-volatile memory retains data when:
Cache memory is typically implemented with:
Main memory is commonly implemented with:
A register is a group of:
The finite state machine model is used to design:
A state variable represents:
Unused states in sequential design should generally be:
A state assignment with fewer bit changes may reduce:
A one-hot state assignment uses:
Binary state assignment tries to use:
The excitation table of a flip-flop tells the inputs needed for:
For a D flip-flop, the required excitation to get next state 1 is:
For a T flip-flop, if present state equals next state, T should be:
For a T flip-flop, if present state must change, T should be:
FSM outputs can be represented conveniently in a:
Synchronous memory interfaces often use control lines such as:
Memory expansion can be done by increasing:
CPLD stands for:
FPGA stands for:
A PLD is mainly used to:
Compared with discrete gates, PLDs usually offer:
An FPGA is built from configurable logic blocks and:
A CPLD usually has architecture based on:
FPGA configuration is typically stored in:
A hardware description language is used to:
Verilog HDL is commonly used for:
VHDL stands for:
A module in Verilog is similar to a:
The keyword used to declare a module in Verilog is:
In Verilog, an always block is commonly used to model:
A continuous assignment in Verilog uses the keyword:
The non-blocking assignment operator in Verilog is:
Non-blocking assignments are generally preferred in clocked always blocks to model:
A testbench is used to:
Simulation helps designers to:
Synthesis converts HDL into:
Timing simulation checks:
A LUT inside an FPGA is primarily used to implement:
An HDL description can be written at behavioral, dataflow, and:
MultiSim is commonly used for:
In laboratory work, waveform viewers help observe:
A pin constraint file in FPGA flow is used to:
A clock constraint in FPGA design is used to:
Debouncing is often needed for:
Metastability is a concern when:
A synchronizer is used to:
Finite state machines on FPGA are usually coded using:
Bitstream file in FPGA flow contains:
A schematic capture tool allows designers to:
Design hierarchy in HDL helps by:
A combinational always block in Verilog should be sensitive to:
The statement `case` in HDL is often used to model:
In FPGA labs, seven-segment displays, LEDs and switches are examples of:
The main purpose of learning HDL in Digital Logic Design is to:





Very good mcqs
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Very good book in DLD
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