Q22. What is meant by the terms multiprogramming and multitasking?
Ans. Multiprogramming refers to presence of more than one user programs, all active, simultaneously in the memory and their execution which takes place in interleaved fashion.
Multitasking refers to simultaneous working of two different tasks inside computer for example, the CPU is executing and side by side the printer is printing.
Q21. What is meant by the term throughput and what is its significance?
Ans. Throughput is the measure of amount of work accomplishment in a given time interval. Higher throughput means better system performance. Throughput is defined as follows:
= (The number of jobs completed) / (Total time to complete the jobs)
Q20. What functions are performed by an operating system as a resource manager?
Ans. (i) Tracing the statue of each resource
(ii) Job selection for processing
(iii) Deciding job’s time share
(iv) Resource allocation to the selected job
(v) Releasing the resource, if time share is elapsed or the job is over.
Q19. What are the functions of an operating system?
Ans. (i) Handling I/O operations that is, device management
(ii) Errors and interrupt handling
(iii) Job scheduling that is, process management
(iv) Security and protection of programs
(v) Providing user interface
(vi) Resource allocation and handling.
Q18. Explain briefly the concept of time-sharing.
Ans. In time sharing, each waiting job is given a fair share of time (time slice) of CPU, as time elapses or any I/O request occurs, CPU shifts over to next waiting job.
Q17. The operating system is called a resource manager. List four distinct resources of the computer system. What are the general functions that the OS performs for these resources?
- Input/output devices
The general functions that OS performs are:
For memory it should be effectively used and allocated to the programs asking for it. There should not be any idle memory and a waiting program at the same time.
For CPU – it should be allocated to the job(s) waiting for it so as to minimize its idle time, increase system’s efficiency and meet job’s deadline if any.
For I/O devices – proper device management that is, allocation of I/O channel and device to a job asking for it, in minimum wait time and ensure user free environment.
For PROGRAMS and DATA – proper storage for them. Ensure their protection and avoid any illegal use of them.
Q16. What purpose does the operating system serve to the computer and the user?
Ans. The operating system narrows the gap between the user and the computer by receiving and interpreting user’s request and then hitting the required work done through the hardware.
Q15. When a folder is copied to another place do the subfolders in the folder also get copied?
Ans. Yes. When a folder is copied to another place, all its subfolders along with their contents also get copied.
Q14. What is the significance of Task bar?
Ans. The taskbar is a bar that shows information about all the open windows. This can also be used to open program (through start button available on it) and switch between open windows.
Q13. What happens when files and folders are deleted in Windows? Is it possible to retrieve deleted objects later? If so how?
Ans. When files and folders are deleted from a hard disk/Windows, they are moved into recycle bin. The files or folders removed from the floppy disks or from the DOS prompt are deleted permanently.
Yes, the deleted objects in recycle bin can be restored. To do so, firstly they are to be selected and then Restore command is clicked at the File menu of Recycle Bin.