Which unit of the CPU decodes instructions and directs the working of the other units without performing any calculation itself?
- A.Arithmetic Logic Unit
- B.Cache memory
- C.Control Unit
- D.Register
Correct answer
Explanation
The correct answer is C, the Control Unit. It fetches each instruction from memory, decodes it, and then issues signals that tell the other parts of the system what to do and when. It manages the flow of data between memory, the arithmetic unit and the input and output devices, but it never performs arithmetic or a comparison itself.
Option A, the Arithmetic Logic Unit, is where all addition, subtraction, multiplication, division and logical comparisons actually happen, so it is precisely the unit the question excludes. Option B, cache memory, is a small very fast memory placed between the processor and main memory to hold frequently used data, and it is a memory rather than a control component. Option D, a register, is the smallest and fastest storage location inside the processor, used to hold an operand or an intermediate result for a moment. The CPU is the sum of the arithmetic unit, the control unit and the registers.
Read the full article: Basics of Computers and Generations: Parts, Memory and MCQs
Practice Questions
View allWho is known as the Father of the Computer?
- A.Blaise Pascal
- B.Charles Babbage
- C.Alan Turing
- D.Herman Hollerith
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He designed the Difference Engine and then the Analytical Engine, and the Analytical Engine contained the logical parts of a modern computer: a store for holding numbers, a mill for calculating, punched-card input and a printed output.
Read the full explanation →Vacuum tubes were used as the main electronic component in which generation of computers?
- A.First generation
- B.Second generation
- C.Third generation
- D.Fourth generation
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Machines such as ENIAC, EDVAC and UNIVAC-I ran on thousands of vacuum tubes, which made them enormous, power-hungry and dependent on constant cooling.
Read the full explanation →The transistor, which defined second-generation computers, was invented at which laboratory?
- A.Texas Instruments
- B.Intel Corporation
- C.Bell Laboratories
- D.IBM Research
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John Bardeen, Walter Brattain and William Shockley demonstrated the transistor there in 1947, and the three shared the Nobel Prize in Physics for it.
Read the full explanation →Which of the following is regarded as the first commercially available electronic computer?
- A.ENIAC
- B.EDVAC
- C.Harvard Mark I
- D.UNIVAC-I
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It was the first electronic computer built to be sold to customers rather than used only in a laboratory, and it was famously put to work on census and business data processing.
Read the full explanation →In which year was the Intel 4004, the first commercial microprocessor, introduced?
- A.1964
- B.1971
- C.1975
- D.1981
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The Intel 4004 placed an entire processing unit on a single chip for the first time in a commercial product, and that step marks the beginning of the fourth generation of computers, built on very large scale integration.
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