Look MCQ Quiz - Objective Question with Answer for Look - Download Free PDF
Last updated on Mar 22, 2025
Latest Look MCQ Objective Questions
Look Question 1:
Consider a disk queue with requests for I/O to blocks on cylinders 218, 12, 30, 11, 94, 128, 345, 205, 380. The LOOK scheduling algorithm is used. The head is initially at cylinder number 150. The cylinders are numbered from 0 to 399. The total head movement (number of cylinders) incurred while servicing these requests is ________. (assume that LOOK algorithm moves towards 399 when it start its execution)
Answer (Detailed Solution Below)
Look Question 1 Detailed Solution
In LOOK algorithm the arm goes only as far as the final request in each direction. Then, it reverses direction immediately, without going all the way to the end of the disk.
Requests will be served in the following sequence:
150, 205, 218, 345, 380, 128, 94, 30, 12, 11
Total head movement:
= 205 – 150 + 218 – 205 + 345 – 218 + 380 – 345 + 380 – 128 + 128 – 94 + 94 – 30 + 30 – 12 + 12 – 11
= 55 + 13 + 127 + 35 + 252 + 34 + 64 + 18 + 1
= 599
Top Look MCQ Objective Questions
Look Question 2:
Consider a disk queue with requests for I/O to blocks on cylinders 218, 12, 30, 11, 94, 128, 345, 205, 380. The LOOK scheduling algorithm is used. The head is initially at cylinder number 150. The cylinders are numbered from 0 to 399. The total head movement (number of cylinders) incurred while servicing these requests is ________. (assume that LOOK algorithm moves towards 399 when it start its execution)
Answer (Detailed Solution Below) 599
Look Question 2 Detailed Solution
In LOOK algorithm the arm goes only as far as the final request in each direction. Then, it reverses direction immediately, without going all the way to the end of the disk.
Requests will be served in the following sequence:
150, 205, 218, 345, 380, 128, 94, 30, 12, 11
Total head movement:
= 205 – 150 + 218 – 205 + 345 – 218 + 380 – 345 + 380 – 128 + 128 – 94 + 94 – 30 + 30 – 12 + 12 – 11
= 55 + 13 + 127 + 35 + 252 + 34 + 64 + 18 + 1
= 599
Look Question 3:
Consider a disk queue with requests for I/O to blocks on cylinders 218, 12, 30, 11, 94, 128, 345, 205, 380. The LOOK scheduling algorithm is used. The head is initially at cylinder number 150. The cylinders are numbered from 0 to 399. The total head movement (number of cylinders) incurred while servicing these requests is ________. (assume that LOOK algorithm moves towards 399 when it start its execution)
Answer (Detailed Solution Below)
Look Question 3 Detailed Solution
In LOOK algorithm the arm goes only as far as the final request in each direction. Then, it reverses direction immediately, without going all the way to the end of the disk.
Requests will be served in the following sequence:
150, 205, 218, 345, 380, 128, 94, 30, 12, 11
Total head movement:
= 205 – 150 + 218 – 205 + 345 – 218 + 380 – 345 + 380 – 128 + 128 – 94 + 94 – 30 + 30 – 12 + 12 – 11
= 55 + 13 + 127 + 35 + 252 + 34 + 64 + 18 + 1
= 599