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Hughes - Software System Test Paper

Hughes Software Systems - Test Paper  

 1) given an expression tree and asked us to write the in fix of that expression four choices 

 2) global variables in different files are 
 a:at compiletime 
b) loading time 
c) linking time 
d)execution time 

 3)size of(int) 
 a) always 2 bytes 
b) depends on compiler that is being used 
c) always 32 bits 
d) can t tell 

 4)which one will over flow given two programs 
 prog 1: prog2: 
main() main() 
{ { 
int fact; int fact=0 
long int x; for(i=1;i<=n;i++) 
fact=factoral(x); fact=fact*i; 
} } 

int factorial(long int x) 

if(x>1) return(x*factorial(x-1); 

a) program 1; 
b) program 2; 
c) both 1 &2 
d) none 

 5) variables of fuction call are allocated in 
 a) registers and stack 
b) registers and heap 
c) stack and heap 

 6) avg and worst case time of sorted binary tree 

 7) data structure used for proority queue 
 a) linked list b) double linkedd list c)array d) tree 

char str[5]="hello"; 
if(str==NULL) printf("string null"); 
else printf("string not null"); 

 what is out put of the program? 
 a) string is null
b) string is not null 
 c) error in program 
 d) it executes but p rint nothing 

 9)there are 0ne 5 pipe line and another 12 pipe line sates are there and flushed time taken to execute five instructions 
 a) 10,17 
b) 9,16 

 10) for hashing which is best on terms of buckets 
 a)100 b)50 c)21 d)32 
 ans 32 

 void f(int value){ 
for (i=0;i<16;i++){ 
if(value &0x8000>>1) printf("1") 
else printf("0"); 

 what is printed? 
 a) bineray value of argument 
 b)bcd value 
 c) hex value 
 d) octal value 

 void f(int *p){ 
static val=100; 

int a=10; 
printf("%d ",a); 
printf("%d ",a); 

 what will be out put? 

 struck a{ 
int x; 
float y; 
char c[10]; 

union b{ 
int x; 
float y; 
char c[10]; 

 which is true? 
 a) size of(a)!=sizeof(b); 

 # define f(a,b) a+b 
#defiune g(c,d) c*d 
find valueof f(4,g(5,6)) 
a)26 b)51 c) d) 

 find avg access time of cache 
 d) tc is time to access cache tm is time to access when miss occure 


char a[10]="hello"; 
strcpy(a,  ); 

out put of the program? 
a) string is null 
 b) string is not null 
 c) program error d) 

 simplyfy k map 
1 x x 0 
1 x 0 1 

int f(int a) 

//some stuff 


 what are x & y types 
 a) x is int y is pointer to afunction which takes integer value 

 19) char a[5][15]; 
int b[5][15]; 
address of a 0x1000 and b is 0x2000 find address of a[3][4] and b[3][4] 
assume char is 8 bits and int is 32 bits 

 20. main() 


 How many times print command is executed? 


int i,*j; 
i= %d",i); 
i= %d",i); 

void f(int*j) 

int k=10; 
j= &k; 

 output is 
a 5 10 
b 10 5 
c 5 5 
d none 

 22. some question on pipeline like you have to findout the total time by which execution is completed for a pipeline of 5 stages. 


int *s = ""; 
if(strcmp(s,NULL)== 0) 
s is null")p 
s is not null"); 

 24. size of integer is 
 a. 2 bytes 
b 4 bytes 
c. machine dependant 
d compiler dependent. 

 25.max and avg. height of sorted binary tree 
 a. logn n 
b n logn 

 26. some question. like the number was shifted everytime by one and bitwise and with 10000000. 

 27. int a[5][4] 
int is 2 bytes base address for array is 4000(Hexa) 
what will be addr for a[3][4]? 
int is 4 bytes same question. 
b) Inasychronous transmission , the time is associated with data itself.... 

  28. implementation of priority queue 
 a. tree 
b linked list 
c doubly linked list. 

Some Questions:

 1. given a digital ckt with nand gates. what is o/p 
 Ans. nor gate 

 2. given an logical expr. x,y,z. simplify 
 ans. xz 

 3. It is recommended to use which type of variables in a recursive module. 
 Ans. static variables. 

 4. which one of following is not memory management model? given buddy system, monitors, paging, swapping 
 Ans. monitors 

 5. what m/c is used to recognize context free grammar ? 
 Ans. pushdown automata 

 6. Which type of grammar can be recognized by finite state m/c Ans. right linear grammar. 

 7.  proc() { 
static i=10; 

If this proc() is called second time, what is the o/p 
 Ans. 11 

 8. int arr[] = {1,2,3,4} 
int *ptr=arr; 
*(arr+3) = *++ptr + *ptr++; 
Final contents of arr[] 
 Ans. {1,2,3,4} 

 9. TCP/IP hdr checksum : what method is used ? 
 Ans. one s complement of sum of one s complement. 

 10. CSMA/Cd is used in which lan 
 Ans. ethernet 

 11.  8085 pgm : LXI sp, 2021, 
LXI b, 1234 (??) 
push b 
contents of stack after pushing ? 

 12. One question on synchronous transmission : 
ans. Timing info is embedded in data itself 

 13. What for start bit is used in RS232 transmission. 

 14. One solution for deadlock prevention for dining philosopher s problem Ans. Allow one person to take first left stick and then right stick and remaining persons in reverse order. 

 15. 4bit seq no in sliding window protocol with selective repeat. what is the max no. of acks that can be held at transmitter 
 ans. 8 

 16. given a height balanced tree. If we add one more node , how many nodes gets unbalanced ? 
 Ans. 3 

 17. Given a arbitrary pointer to an element in a singly linked list? what is the time complexity for its deletion . 
 Ans. O(n) 

 18. what is the diff b/n c and c++ 
 a. dynamic scoping 
b. nested switching 
c. declaration of variables in any code block 
d. separation of compilation and linking 
 Ans. c (??) 

 19. which one is false ? 
 a. 0 b. root of log(n) = O(log logn) 
c. O(logn/100) = O(100 logn) 
d. 2n not = O(n power k); 
Ans. b or a. (??) 

 20. S->S+S; s->s*s; s->a how many parse trees possible : a+a*a+a 
 Ans. 5 

 21. 4-1 demultiplexer is to be implemented using a memory chip. how many address lines and word length required 
Ans. 4, 1 

 22. Vector intr mechanism. in 8085. 
 Ans. fixed locations in memory when an intr comes. 

 23. ARP is used for : Ans. IP to MAC addr conversion.  

 24. given 100 to 999 nos. Probability of picking a no. with out digit 7. 
 Ans. 18/25. 

 25. Ten film rolls. 3 defective, prob. of picking up 2 defective rolls with out replacement 
 Ans. 6/90 

 26. The purpose of hashing is : 
 Ans. O(1) complexity 

 27. Given adjacency matrix for a directed graph with n vertices and e edges. How much time will it take to find out indegree of a vertex 
 Ans. O(n) 

 28. No. of nodes of degree 2 in a binary tree with n leaf nodes. 
 Ans. n-1 

More Questions: 

 1) find the probability of getting a number with 7 between 100 and 999 (both inclusive). 

 2) There are 10 items in a box, out of which 3 are defective. 2 balls are taken one after the other. what is the probability that both of them are defective? 
 Ans: 1/15 or 6/90 

 3) Context free grammar is accepted by 
 a) finite automata 
b)push down automata 
c) two way bounded automata 
d) both b and c 

 4) which is not a memory management scheme? 
 a) buddy system 
b) swapping 
c) monitors 
d) paging Ans : c 

 5) qn. on karnaugh map for simplifying boolean expressions 

- 1 1 - 
1 - - 1 
1 - - 1 
- 1 1 - 
karnaugh map 

 6) qn. on nand gates . 

 7) context sensitive grammar 

 8) An identifier can start with a letter followed by any number of letter or digits . 
 ans: L.(LUD)* 

 9) 8MB total memory, 256 k cache , 4k is block size. direct mapping how many different physical memory blocks can be mapped on to the cache. 
a) 64             b) 256                 c) 128 

 10) CSMA/CD is used in 
 a) token ring 
b) FDDI 
d) ethernet 
 Ans : d 

 11) In TCP/IP header , checksum contains 
 a) sum of all the words 
b) ones complement of the data 
c) ones complement of the sum of all the words 
d) ones complement of the sum in ones complement 
 Ans : d 

 12) Max no of Acknowledgements for a 4 bit sequence number in a sliding window protocol. 

 13) which is a good way of representing varaibles in recursion 
 a) local variables 
b) static varaibles 
c) global variables 

 14) c programs 
 func() { 
static int i = 10; 

 what is the value of i if the function is called twice ? 

 Ans : 11 

 15) Qn. on pointers . 

 16) given page table,page size and offset find the corresponding physical address ? 
 ans : a (3*1024+576) (pageno*pagesize+offset) 

 17) In a memory chip 4k size and 16bit words to be stored. No of address and data lines reqd. 
 Ans) 16 data and 12 address 

 18) idetify in which pass of the 2 pass compiler 
 1) literals 
2) address resolution 
3) listing 

 19) object code not requires 
 a) relocation bits 
b) external names and place where they are located 
c) absolute adress 
d) all the object codes 

 20) ARP 
 a) MAC to IP 
b) IP to MAC 
 Ans : b 

 21) Qn on Balanced tree ? A balanced tree is given and a node is addded at the leaf and asked to find the no of unbalanced nodes? 

 22) order of Hashing time 
 a) 0(1) 
b) 0(n2) 

 4) parse tree 
 s -> s + s ; s -> s * s ; s -> a 
find the no of parse trees for a+a*a+a 
a) 4 
b) 5 
c) 6 
 ans: 5 

 25) order of deleting an node from a linked list. (pointer is to an arbitrary node) 

 26) A choclate of size nXn is given and is to be made into pices of size 1x1. At a time both horizontal and a vertical cut is done. Find the order of complexity 
 a) 0(n2) 
b) o(nlogn) 
c) o(logn) 
 Ans : a 

 27) A directed graph is represented by adjacency list. To find the complexity of indegree of the node. e - edge n- vertices 
 a) o(e+n) 

 28) No of leaf nodes given. find the no of nodes with degree 2. 

 29) AX = B . A is mXn and B is mX1 and several options given like 
 a) there is a unique solution if rank of A is same as rank of augumented matrix [A b] 
b) there are multiple solutions 

 30) LXI sp,2099h LXI b, 2012h push b 

31) Which of the following are false (on complexities) 

 32) A,B are sets. A s cardinality is m and B s is n where m < n how many one to one mappings can be obtained. 
 a) n ^ m 
b) npm 
c) mpn 
d) mcn 

 33) In scduling algorithnms which are logically executed but suspended 
 a) preemptive 
b) SJF 
c)non preemptive 
d) all the above 
 Ans : a 

 34) I/O redirection is 
 a) copying programs files through a pipe 
b) input files are created 
c) input file taken from existing ones 
d) none 

 35) symmetric multiprocessing can be done in 
 a) snoopy protocols 
b) cache coherence 

 36) dining philospheres problems to avoid dead lock 
 a) 1 person will take left one and all other will take right one 
b) adjacent persons should not eat concurrently 

 36) process states ? which is the correct order 
 a) timeout:ready -> running 
b) blocked : ready -> running 

 37) for converting infix expression to postfix what 
 do we require 
a) operand stack 
b) operator stack 

 38) 0 is reprented as both and negative and positive 
 a) ones complement 
b) twos complement 
c) two s complement has extra negative number 

 39) Difference between c and c++? 
 a)In c++ we can define variables in the middle 
b)dynamic scoping 

 40) Which of the following is correct 

a) Synchronous tranmission needs more badwidth than Asychronous. 


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