1.What is an operating system?
An operating system is a program that manages the computer hardware. it act as an intermediate
between a users of a computer and the computer hardware. It controls and coordinates the use of the
hardware among the various application programs for the various users.
2.What is the kernel?
A more common definition is that the OS is the one program running at all times on the computer
3.What are batch systems/
Batch systems are quite appropriate for executing large jobs that need little interaction. The user
can submit jobs and return later for the results. It is not necessary to wait while the job is processed.
4.What is graceful degradation?
In multiprocessor systems, failure of one processor will not halt the system, but only slow it down
by sharing the work of failure system by other systems. This ability to continue providing service is
proportional to the surviving hardware is called graceful degradation.
5.Differentiate Tightly coupled systems and loosely coupled systems?
Loosely coupled systems
Tightly coupled systems
Each processor has its own local memory
Common memory is shared by many processors
Each processor can communicate with other all
through communication lines
No need of any special communication lines
6.What is real time system?
A real time system has well defined ,fixed time constraints. Processing must be done within the
defined constraints, or the system will fail. It is often used as a control device in a dedicated application.
7.What are privileged instructions?
Some of the machine instructions that may cause harm to a system are designated as privileged
instructions. The hardware allows the privileged instructions to be executed only in monitor mode.
8.What do you mean by system calls?
System calls provide the interface between a process and the operating system. When a system
call is executed, it