Most Important Questions for UGC NET

1. IP datagram has arrived with following partial information in the header (in hexadecimal)

45000054000300002006....

What is the header size?
1. 10 bytes
2.20 bytes
3.30 bytes
4. 40 bytes
Solution -(2) 20 bytes

2. IP datagram has arrived with following partial information in the header (in hexadecimal)

45000054000300002006....

What is the efficiency of this datagram?
1.76.19%
2.80.50%
3.82.24%
4.85.45%
Solution -(1) 76.19%

3. IP datagram has arrived with following partial information in the header (in hexadecimal)

45000054000300002006....

What is the size of datagram?
1. 64 bytes
2. 74 bytes
3. 84 bytes
4. 104 bytes
Solution -(3) 84 bytes

4. IP datagram has arrived with following partial information in the header (in hexadecimal)

45000054000300002006....

How many more routers can the packet travel to?
1.22
2.26
3.30
4.32

Solution -(4) 32

5. IP datagram has arrived with following partial information in the header (in hexadecimal)

45000054000300002006....

What is the protocol of the payload being carried by the packet?
1. ICMP
2. SCTP
3. TCP protocol
4. IGMP
Solution -(3) TCP protocol

6. Consider the following program fragment that deals with a table T with 17 rows and 1024 columns. computing an average for each column and printing it to screen (i is row index and j is column index):

for j [0..... 1023]{
temp = 0;
for i = [0.... 16]:
temp = temp+T [i] [j]:
print (temp/ 17.0); }

T[i] [j] and temp are 32 bit floating point values and memory is word addressable. The temporary variable temp is kept in a processor register so access to temp does not involve a memory reference. The main memory is page and holds 16 pages of size 1024 words, the page replacement policy is "least recently used ". If T is stored in the virtual address space in row major format.

Consider again that T is stored in column-major format. what is the main memory hit ratio?
1.80%            
2.95.6%
3.97.8%          
4.99.9%

Solution -(4) 99.9%

7. Consider the following program fragment that deals with a table T with 17 rows and 1024 columns. computing an average for each column and printing it to screen (i is row index and j is column index):

for j [0..... 1023]{
temp = 0;
for i = [0.... 16]:
temp = temp+T [i] [j]:
print (temp/ 17.0); }

T[i] [j] and temp are 32 bit floating point values and memory is word addressable. The temporary variable temp is kept in a processor register so access to temp does not involve a memory reference. The main memory is page and holds 16 pages of size 1024 words, the page replacement policy is "least recently used ". If T is stored in the virtual address space in row major format.

How many page faults will be encountered?
1. 16,402             
2. 17,408
3.18.208             
4. 18.608

Solution -(2) 17,408
8. Consider the following program fragment that deals with a table T with 17 rows and 1024 columns. computing an average for each column and printing it to screen (i is row index and j is column index):

for j [0..... 1023]{
temp = 0;
for i = [0.... 16]:
temp = temp+T [i] [j]:
print (temp/ 17.0); }

T[i] [j] and temp are 32 bit floating point values and memory is word addressable. The temporary variable temp is kept in a processor register so access to temp does not involve a memory reference. The main memory is page and holds 16 pages of size 1024 words, the page replacement policy is "least recently used ". If T is stored in the virtual address space in row major format.

What is fault ratio of row major to column major arrangements ?
1. 1024:1           
2. 1301:1
3. 1240:1            
4. 9107:8
Solution -(1)  1024:1 

9. Consider the following program fragment that deals with a table T with 17 rows and 1024 columns. computing an average for each column and printing it to screen (i is row index and j is column index):

for j [0..... 1023]{
temp = 0;
for i = [0.... 16]:
temp = temp+T [i] [j]:
print (temp/ 17.0); }

T[i] [j] and temp are 32 bit floating point values and memory is word addressable. The temporary variable temp is kept in a processor register so access to temp does not involve a memory reference. The main memory is page and holds 16 pages of size 1024 words, the page replacement policy is "least recently used ". If T is stored in the virtual address space in row major format.

Consider that T is stored in column major format, how many page faults will be encountered?
1.14            
2.15
3.16          
4.17
Solution -(4) 17

10. Consider the following program fragment that deals with a table T with 17 rows and 1024 columns. computing an average for each column and printing it to screen (i is row index and j is column index):

for j [0..... 1023]{
temp = 0;
for i = [0.... 16]:
temp = temp+T [i] [j]:
print (temp/ 17.0); }

T[i] [j] and temp are 32 bit floating point values and memory is word addressable. The temporary variable temp is kept in a processor register so access to temp does not involve a memory reference. The main memory is page and holds 16 pages of size 1024 words, the page replacement policy is "least recently used ". If T is stored in the virtual address space in row major format.

What is the main memory hit ratio?
1. 0            
2. 1
3. 2             
4. 3
Solution -(1) 0