OS QUIZ 2

Which of the following is NOT a memory management technique?

• Paging

• Segmentation

• Swapping

• Scheduling

What is internal fragmentation?

• Unused memory blocks that are never allocated
• Memory fragmentation caused by external factors
• Internal fragmentation is the wasted space within allocated memory blocks due to inefficient memory usage.
• Memory allocated without any usage

What is the size of a page table(in Mega Bytes) in a system with 32-bit virtual addresses and 4KB page size, assuming each page table entry is 4 bytes?

The phenomenon where the CPU spends more time swapping pages than executing processes is called:

• Segmentation

• Fragmentation

• Swapping

• Thrashing

A system uses a TLB (Translation Lookaside Buffer) to speed up virtual address translation. The following parameters are given:

• TLB access time = 10 ns

• Memory access time = 100 ns

• TLB hit ratio = 80%

Assume that on a TLB hit, only one memory access is needed (to access the actual data). On a TLB miss, two memory accesses are required (one for page table lookup and another to access data).

Calculate the Effective Memory Access Time (EMAT).

• 130 ns
• 200 ns
• 90 ns
• 150 ns

The time taken to move the disk arm to the desired track is called:

• Latency time
• Seek time
• Transfer time
• Access time

What is rotational latency?

• A. Time taken to format the disk

• Time for desired sector to rotate under the read/write head

• The time taken to access the memory cache.
• Time to move disk arm to correct track

In Round Robin scheduling, if time quantum is too large, it behaves like:

• First-Come, First-Served (FCFS) scheduling.
• Multilevel Queue scheduling.
• Priority scheduling.
• Shortest Job First (SJF) scheduling.

Which scheduling algorithm gives minimum average waiting time for a given set of processes?

• Priority Scheduling
• Shortest Job First (SJF)
• Round Robin (RR)
• First-Come, First-Served (FCFS)

Consider the following page reference string:

7, 0, 1, 2, 0, 3, 0, 4, 2, 3

Assume the system has 3 page frames and uses the FIFO (First-In-First-Out) page replacement algorithm.

Calculate the number of page faults.

• 9

• 7
• 4
• 5