Computer Knowledge
Digital Logic and Microprocessors
735 Questions
Digital logic and microprocessors form the core of computer science, covering logic gates, combinational and sequential circuits, and CPU architecture. These topics are crucial for computer knowledge sections in technical exams. Test your digital electronics basics here.
Logic gates and circuitsCombinational vs sequential circuitsMicroprocessor instructionsTruth tables and boolean functions
Digital Logic and Microprocessors Questions
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Encoder
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Decoder
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Half Adder(HA)
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Full Adder (FA)
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makes logic decisions
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allows electron flow only in one direction
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Both A and B
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None of these
A
Correct answer
Explanation
A logic gate is an electronic circuit that performs Boolean logic operations on binary inputs to produce binary outputs - essentially making logic decisions. Option B describes a diode, not a logic gate. Since B is incorrect, 'Both A and B' cannot be correct.
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Hard disk
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microprocessor
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transistor
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flip-flops
D
Correct answer
Explanation
Flip-flops are bistable multivibrators that can store one bit of binary data (0 or 1) in sequential circuits. They are the basic storage elements used in registers, counters, and memory. Unlike hard disks which are storage devices, flip-flops are the actual circuit elements that maintain binary state within digital systems.
D
Correct answer
Explanation
The cost of computing has decreased dramatically since the 1960s. From over $1 billion per FLOP in the 1960s, costs have fallen to pennies due to Moore's Law and technological advances. The current cost is approximately $0.14 per FLOP, representing an improvement of over 10 billion times.
B
Correct answer
Explanation
One NAN can contain multiple EANs, multiple UPCs, or multiple RACs, not just one. The system allows a NAN to aggregate or be associated with multiple identifiers. The statement that it contains only one of each type is false.
B
Correct answer
Explanation
One NAN CAN contain multiple EANs, UPCs, or RAC codes. A single national article number represents all variants and pack sizes of a product, each with its own barcode. The claimed answer (False) correctly identifies that the restriction is not true.
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Arithmetic Logic Unit
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Array Logic Unit
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Application Logic Unit
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None of above
A
Correct answer
Explanation
ALU (Arithmetic Logic Unit) is a digital circuit that performs arithmetic and logical operations. It is a fundamental component of a computer's CPU. 'Array' and 'Application' are incorrect expansions.
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Odd parity bit
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Even parity bit
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Both of the above
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None of above
C
Correct answer
Explanation
Both odd parity and even parity bits are used for error detection. Parity bits add an extra bit to make the total number of 1s either odd (odd parity) or even (even parity), helping detect single-bit errors during transmission.
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Input is first converted to digital form
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Input is never converted to digital form
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Output is displayed in digital form
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All of the above
B
Correct answer
Explanation
Analog computers process continuous physical signals (electrical voltages, mechanical movements) directly without converting them to digital binary form. They use analog components like operational amplifiers to perform mathematical operations through continuously varying signals. Digital computers must first convert analog inputs to digital form, but analog computers work entirely in the continuous domain.
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Rectifier
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Flip-Flop
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Comparator
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Attenuator
B
Correct answer
Explanation
A flip-flop is a bistable multivibrator circuit that can store one bit of binary information (0 or 1) and is the fundamental building block of memory systems. Rectifiers convert AC to DC, comparators compare voltages, and attenuators reduce signal power - none store data.
A
Correct answer
Explanation
In digital logic, an 'inhibitor' is a gate where one input can prevent the output from being active. If one input of an AND gate is inverted (using a NOT gate), that input acts as a control that 'inhibits' the output when it is high.
A,B
Correct answer
Explanation
Both NAND and NOR are universal gates because you can build any logic function (AND, OR, NOT) using only NAND or only NOR gates. This property makes them fundamental in digital circuit design.
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combitional circuit and memory elements
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only combinational circuit with clock
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gate and clock pluse
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any of these
A
Correct answer
Explanation
Sequential circuits depend on both current inputs and previous states, requiring memory elements (flip-flops) to store state information. Combinational circuits alone cannot remember past inputs. Option A correctly identifies both components are needed.
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bubbled AND
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bubbled OR
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bubbled XOR
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NONE OF THESE
A
Correct answer
Explanation
NAND = AND followed by NOT. In gate symbolism, this is represented as an AND gate with a bubble (inversion circle) at its output. This is called a bubbled AND gate. Alternative equivalent representations include OR with bubbles at all inputs (De Morgan's law), but bubbled AND is the direct representation.
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AND , OR
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NAND
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NOR
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OR,AND,NOT
A
Correct answer
Explanation
The set {AND, OR} cannot express negation or complement operations, making it functionally incomplete. In contrast, NAND and NOR are each individually complete, and {AND, OR, NOT} is also complete.