The root directory of a disk should be placed:

A certain moving arm disk storage, with one head, has the following specifications.
Number of track/recording
Surface $$=200$$
Disk rotation speed $$=2400$$$$rpm$$
Track storage capacity $$=62,500$$ $$bits$$
The average latency of this device is
$$P$$ $$msec$$ and the data transfer rate is
$$Q$$ $$bits / sec.$$ Write the value of $$P$$&$$Q$$

State whether the following statement are TRUE or FALSE with reason. The data transfer between memory and $${\rm I}/O$$ devices using programmed $${\rm I}/O$$ is fasterthan interrrupt-driven $${\rm I}/O$$.

Disk requests come to disk driver for cylinders $$10,22,20,2,40,56$$ and $$38,$$ in that order at a time when the disk drive is reading from cylinder $$20.$$ The seek time is $$6msec$$ per cylinder. Compute the total seek time if the disk arm scheduling algorithm is
(a) First come first served
(b) Closest cylinder next.