Consider the following table of arrival time and burst time for three processes $$P0,P1$$ and $$P2$$.

Process	Arrival Time	Burst Time
P0	0 ms	9 ms
P1	1 ms	4 ms
P2	2 ms	9 ms

The pre-emptive shortest job first scheduling algorithm is used. Scheduling is carried out only a arrival or completion of processes. What is the average waiting time for the three processes?

Let the time taken to switch between user and kernel modes of execution be $${t_1}$$ while the time taken to switch between two processes be $${t_2}$$.

Which of the following is TRUE?

A thread is usually defined as a ''light weight process'' because an operating system $$(OS)$$ maintains smaller data structures for a thread than for a process. In relation to this, which of the following is TRUE?

A Computer handles several interrupt sources of which the following are relevant for this question:

$$ * \,\,\,$$ Interrupt from $$CPU$$ temperature sensor (raises interrupt if $$CPU$$ temperature is too high)

$$ * \,\,\,$$ Interrupt from Mouse (raises interrupt if the mouse is moved or a button is pressed)

$$ * \,\,\,$$ Interrupt from keyboard (raises interrupt when a key is pressed or release)

$$ * \,\,\,$$ Interrupt from Hard Disk (raises interrupt when a disk read is completed)>/p>

Which one these will be handled at the HIGHEST priority?