Which one of the following statements is not correct with regard to the UNIX operating system ?
- A.It is written in C.
- B.It is portable to a variety of computers.
- C.It is a multi-user operating system.
- D.It cannot be time-shared by several users.
Correct answer
Explanation
The correct answer is D, It cannot be time-shared by several users. UNIX was designed from the start as a time-sharing system, so this statement is false.
UNIX was developed at Bell Labs from 1969 by Ken Thompson and Dennis Ritchie. In 1973 it was rewritten in the C language, which Ritchie had created, and this made it one of the first operating systems that could be moved to different hardware with little change. It is multi-user and multitasking: the processor's time is shared among many users and programs, each getting short turns so that all seem to run at once. Linux, macOS and Android all follow ideas that began with UNIX.
A is correct: UNIX is written mostly in C, with a small part in assembly. B is correct: being written in C made it portable to many kinds of computers. C is correct: several users can log in and work on one UNIX machine at the same time.
Exam tip: UNIX, Bell Labs 1969, Thompson and Ritchie; written in C, portable, multi-user and time-sharing.
Practice Questions
View all1 gigabyte in binary system is equivalent to
- A.1000 kilobytes
- B.1024 megabytes
- C.1200 megabytes
- D.10000 kilobytes
Show answer
In the binary system every step up the ladder of memory units is a factor of 2 raised to 10, that is 1024, so one gigabyte holds 1024 megabytes.
Read the full explanation →Consider the following:
1. Small memory
2. Less expensive memory
3. Fast memory
Which of the above are the characteristics of the cache memory?
- A.1 and 2 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
Show answer
Cache memory is small and very fast, but it is the most expensive memory per byte after the CPU registers, so statement 2 is wrong.
Read the full explanation →What is the correct term used for a set of wires used to connect different internal components of the computer system for the purpose of transferring data as well as addresses amongst them?
- A.Hub
- B.Port
- C.Router
- D.Bus
Show answer
A bus is the shared set of electrical lines on the motherboard that carries data, addresses and control signals between the CPU, memory and input-output devices.
Read the full explanation →Which one of the following is an application of Artificial Intelligence?
- A.Database management system
- B.Operating system
- C.Natural language processing
- D.Register
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NLP is the branch of artificial intelligence that lets computers understand, interpret and produce human language. Artificial intelligence covers systems that perform tasks normally needing human intelligence, such as learning, reasoning and understanding speech or text.
Read the full explanation →Which one among the following computer languages is the oldest?
- A.Prolog
- B.C++
- C.Java
- D.Fortran
Show answer
Released by IBM in 1957, Fortran is the oldest of the four and is often called the first widely used high-level programming language.
Read the full explanation →