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    1) a certain moving arm disk storage with one head has following specifications: 
No. of tracks / recording surface = 200 
Disk rotation speed = 2400 rpm 
Track storage capacity = 62500 is 
What is the average latency time (assume the head can move from one track to another only by traversing the entire track ) and the transfer rate 
a) 2.9 sec and 4.25 Mbits/sec b) 2.5 sec and 2.5 Mbits/sec c) 3.1 sec and 1.5 Mbits/sec d) 3.1 sec and 1.5 Mbits/sec 

2) For each process Pi , i = 1, 2, 3, ……9 is coded as follows 
Repeat 
P(mutex) 
{critical section} 
forever. 
The code for P10 is identical expect that it uses V(mutex) in place of p(mutex) . What is the largest number of processes that can be inside the critical section at any moment ? 
a) 1 b) 2 c) 3 d) none of these 

3) a high speed tape system accommodates 2400 ft reel of standard track tape. The tape is moved fast at the rate 150 inches / sec. 
i ) What must be the linear tape recording density in order to achieve a data transfer rate of 106 bit/sec. 
a) 6667 bpi b) 4096 bpi c) 6196 bpi d) 8192 bpi 

ii) If tape is organized into blocks of 32 Kb, a gap of 0.4 inches separates the blocks, what is the storage capacity of the tape 
a) 16 MB b) 16.4 MB c) 8 MB d) 23.2 MB 

4) The functionality of automatic TEST-AND-SET assembly language instruction is given by the following ‘C’ function? 
Int TEST-AND-SET(int *x) 
{ 
int y; 
a1 : y = *x; 
a2 : *x = 1; 
a3 : return y; 
} 

C functions for implementing code for entering and leaving critical section based on the above TEST-AND-SET instruction. 

Int mutex = 0; 
Void enter-cs() 
{ 
while( (1) ); 
} 

void leave-cs() 
{ 
(2); 
} 

What is values of (1) and (2)? 
a) TEST-AND-SET(mutex) , mutex = 0; 
b) TEST-AND-SET(mutex) , mutex = 1; 
c) TEST-AND-SET(mutex) , mutex = 0; 
d) TEST-AND-SET(mutex) , mutex = 1; 

5 ) In a cache-organized memory there exists 30% of compulsory misses, 20% capacity misses, 12% conflict misses. If the cache is full associative, find the average access time? (t(c) = 19ns , t(m) = 100ns) 
a) 10ns b) 40 ns c) 30 ns d) 62 ns 

6) What is the hit-ratio for this code in a direct-mapped write back , write allocate data cache with cache size 32 KB and block size 16 KB? 
a) 2/3 b) 5/6 c) 3/4 d) 7/8 

7) Consider a disk having 8 surfaces, each surface is having an outer diameter of 16 cm and inner diameter of 6 cm, inner track space is 0.2 mm . There are 32 sectors in each track. If the disk address for reading a byte of a sector on any surface track of the disk is 27 bits. 

i) What is the sector size? 
a) 2 KB b) 4 KB c) 512 KB d) 256 KB 

ii) If the above disk rotates at 3600 rpm, what is the effective data transfer rate in bytes/sec? 
a) 4 MB/sec b) 3.5 MB/sec c) 3.8 MB/sec d) None 

Author	Message
manju Senior Member Joined: 20Feb2007 Online Status: Offline Posts: 221	Topic: operating systeem questions Posted: 22Feb2007 at 2:31pm
	1) a certain moving arm disk storage with one head has following specifications: No. of tracks / recording surface = 200 Disk rotation speed = 2400 rpm Track storage capacity = 62500 is What is the average latency time (assume the head can move from one track to another only by traversing the entire track ) and the transfer rate a) 2.9 sec and 4.25 Mbits/sec b) 2.5 sec and 2.5 Mbits/sec c) 3.1 sec and 1.5 Mbits/sec d) 3.1 sec and 1.5 Mbits/sec 2) For each process Pi , i = 1, 2, 3, ……9 is coded as follows Repeat P(mutex) {critical section} forever. The code for P10 is identical expect that it uses V(mutex) in place of p(mutex) . What is the largest number of processes that can be inside the critical section at any moment ? a) 1 b) 2 c) 3 d) none of these 3) a high speed tape system accommodates 2400 ft reel of standard track tape. The tape is moved fast at the rate 150 inches / sec. i ) What must be the linear tape recording density in order to achieve a data transfer rate of 106 bit/sec. a) 6667 bpi b) 4096 bpi c) 6196 bpi d) 8192 bpi ii) If tape is organized into blocks of 32 Kb, a gap of 0.4 inches separates the blocks, what is the storage capacity of the tape a) 16 MB b) 16.4 MB c) 8 MB d) 23.2 MB 4) The functionality of automatic TEST-AND-SET assembly language instruction is given by the following ‘C’ function? Int TEST-AND-SET(int x) { int y; a1 : y = x; a2 : x = 1; a3 : return y; } C functions for implementing code for entering and leaving critical section based on the above TEST-AND-SET instruction. Int mutex = 0; Void enter-cs() { while( (1) ); } void leave-cs() { (2); } What is values of (1) and (2)? a) TEST-AND-SET(mutex) , mutex = 0; b) TEST-AND-SET(mutex) , mutex = 1; c) TEST-AND-SET(mutex) , mutex = 0; d) TEST-AND-SET(mutex) , mutex = 1; 5 ) In a cache-organized memory there exists 30% of compulsory misses, 20% capacity misses, 12% conflict misses. If the cache is full associative, find the average access time? (t(c) = 19ns , t(m) = 100ns) a) 10ns b) 40 ns c) 30 ns d) 62 ns 6) What is the hit-ratio for this code in a direct-mapped write back , write allocate data cache with cache size 32 KB and block size 16 KB? a) 2/3 b) 5/6 c) 3/4 d) 7/8 7) Consider a disk having 8 surfaces, each surface is having an outer diameter of 16 cm and inner diameter of 6 cm, inner track space is 0.2 mm . There are 32 sectors in each track. If the disk address for reading a byte of a sector on any surface track of the disk is 27 bits. i) What is the sector size? a) 2 KB b) 4 KB c) 512 KB d) 256 KB ii) If the above disk rotates at 3600 rpm, what is the effective data transfer rate in bytes/sec? a) 4 MB/sec b) 3.5 MB/sec c) 3.8 MB/sec d) None Post Resume:* Click here to Upload your Resume & Apply for Jobs

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balu Senior Member Joined: 20Feb2007 Online Status: Offline Posts: 236	Posted: 22Feb2007 at 2:33pm
	Here , I find the average Latency Time ., It 's (60 / 2400) = 0.025 = 2.5.. so ,the answer will be option (b)..... But , I am little bit Suspect abt the Transfer time , According to equation = (60/2400)*(62500/200) , Which is Not match WIth the option (b). pls Give me , What is the possible Transfer time Equation... I am littl;e bit Suspect abt the Option (b) option .. Is it Right or Wrong ? pls Verift It..
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