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ISRO Sample Paper for Research Program

Apr 23 • Competition Sample Papers • 8038 Views • 7 Comments on ISRO Sample Paper for Research Program

The main aim of ISRO(Indian Space Research Organisation) is to develop space technology and implementing it for various national task.It has successfully operationalised two satellite system which helped in management of natural resources.It is one of the largest government agencies in the world.It has achieved a lot since its establishment.It conducts exams for various fields and recruit candidates.

ISRO Sample Paper For Research Program

This paper consists of 80 multiple choice questions each carrying +3 marks for correct answer and -1 for wrong answer.

The full set covers the full syllabus of Computer Science and Engineering Department.

All questions are mandatory.

Full Marks:240                                                                                          Time:90 minutes

1. The equivalent postfix expression will be: ( A – B ) * ( C / D ) + E

a. ABCDE*/-+

b. AB-CD/*E+

c. CDE/+AB*-

d. AB*-CD/+E

2. The principle of locality of reference justifies the use of

a. Virtual memory

b. Interrupts

c. Main memory

d. Cache memory

3. How many 2-input multiplexers are required to construct a 210 – input multiplexer?

a. 1023

b. 31

c. 10

d. 127

4. The switching expression corresponding to f(A,B,C,D) = ∑(1,4,5,9,11,12)

a. BC’D’+A’C’D+AB’D


c. ACD’+A’BC’+AC’D’


5. Consider a set of 5 processes whose arrival time, CPU time needed and the priority are given below

Process Priority       Arrival Time (in ms)            CPU time needed (in ms)             Priority

P1                                 0                                        10                                   5

P2                                 0                                         5                                    2

P3                                 2                                         3                                    1

P4                                 5                                        20                                    4

P5                                 10                                       2                                     3

(Smaller the number, higher the priority)

If the CPU scheduling policy is priority scheduling without pre-emption, the average waiting time will be

a. 12.8 ms

b. 11.8 ms

c. 10.8 ms

d. 09.8 ms

6. The terminal multiplexer has six 1200 bps terminals and ‘n’ 300 bps terminals connected to it. The outgoing line is 9600 bps. What is the maximum value of ‘n’?

a. 4

b. 16

c. 8

d. 28

7. The initial configuration of a queue is a, b, c, d (a is in the front end). To get the configuration d, c, b, a one needs a minimum of

a. 2 deletions and 3 additions

b. 3 deletions and 2 additions

c. 3 deletions and 3 additions

d. 3 deletions and 4 additions

8. For a database relation R (a, b, c, d) where the domains of a, b, c and d include only atomic values, only the following functional dependencies and those that can be inferred from them hold

a -> c

b -> d

the relation is in

a. First normal form but not in second normal form

b. Second normal form but not in third normal form

c. Third normal form

d. None of the above

9. The set of all equivalence classes of a set A of cardinality C

a. Is of cardinality 2C

b. Has the same cardinality as A

c. Forms a partition of A

d. Is of cardinality C2

10. On a system using non pre-emptive scheduling, the processes with expected run times of 5, 18, 9 and 12 are in the ready queue. In what order should they be run to minimize wait time?

a. 5, 12, 9, 18

b. 5, 9, 12, 18

c. 12, 18, 9, 5

d. 9, 12, 18, 5

11. The average case and worst case complexities for Merge sort algorithm are

a. O(n2) and O(n2)

b. O(n2) and O(n log2 n)

c. O(n log2 n) and O(n2)

d. O(n log2 n) and O(n log2 n)

12. The micro instructions stored in the control memory of a processor have a width of 26 bits. Each micro instruction is divided into three fields: a micro-operation field of 13 bits, a next address field (X) and a MUX select field (Y). There are 8 status bits in the inputs of the MUX. How many bits are there in X and Y fields, and what is the size of control memory in number of words?

a. 10, 3, 1024

b. 8, 5, 256

c. 5, 8, 2048

d. 10, 3, 512

13. The idea of cache memory is based on

a. Property of locality of reference

b. Fact that only a small portion of a program is referenced relatively frequently

c. Heuristic 90-10 rule

d. Fact that references generally tend to cluster

14. (10110011100011110000)2 in base 32 is

a. 22 14 7 16

b. 11 9 23 31

c. 11 9 7 16

d. 11 14 23 16

15. The addressing mode used in PUSH B is

a. Direct

b. Register

c. Register indirect

d. Immediate

16. Consider three CPU-intensive processes, which require 10, 20 and 30 time units and arrives at times 0, 2 and 6 respectively. How many context switches are needed if operating system implements a shortest remaining time first algorithm? Don not count the context switches at time 0 and at the end.

a. 1

b. 2

c. 3

d. 4

17. In a B-tree of order 5, the following keys are inserted as follows: 7, 8, 1, 4, 13, 20, 2, 6, 5. How many elements are present in the root of the tree?

a. 1

b. 2

c. 3

d. 4

18. What is the most appropriate data structure to implement a priority queue?

a. Heap

b. Circular array

c. Linked list

d. Binary tree

19. In an absolute loading scheme, which loader function is accomplished by loader?

a. Re-allocation

b. Allocation

c. Linking

d. Loading

20. Which model is simplest model in software development?

a. Waterfall

b. Iterative

c. Prototyping

d. None of these

21. Remote Computing Service uses the time sharing and

a. Multi processing

b. Interactive processing

c. Batch processing

d. Real-time processing

22. The cost of network is usually determined by

a. Time complexity

b. Switching complexity

c. Circuit complexity

d. None of these

23. Which of the following logic has the maximum fan out?

a. RTL

b. ECL

c. N MOS

d. C MOS

24. Highest noise margin is offered by


b. TTL

c. ECL

d. C MOS

25. The ATM cell is

a. 48 bytes long

b. 53 bytes long

c. 64 bytes long

d. 69 bytes long

26. Which of the following regular expressions corresponds to this grammar?

S -> AB / AS                                                                                                                                                   A -> a / aA                                                                                                                                                       B -> b

a. aa*b+

b. aa*b

c. (ab)*

d. a(ab)*

27. Enumeration variables can be used in:

a. Search statements like an integer variables

b. Break statements

c. Pre-processor commands

d. Function statements

28. In DBMS, deferred update means

a. All updates are done first but the articles are made in long files later

b. All the log file entries are made first but the actual updates are done later

c. Every update is done first followed by writing on the log

d. Changes in the views are deferred till a query asks for a view

29. What is the time required to insert an element in a stack with linked implementation?

a. O(log2 n)

b. O(n)

c. O(n log2 n)

d. O(1)

30. Linking:

a. Cannot be performed before relocation

b. Cannot be performed after relocation

c. Can be performed both before and after relocation

d. Is not required if relocation is performed

31. Loading operating system from secondary memory to primary memory is called _______

a. Compiling

b. Booting

c. Refreshing

d. Reassembling

32. The first operating system of Microprocessor is


b. CP/M


d. T.H.E

33. Software Risk assessment involves which two tasks?

a. Risk magnitude and risk impact

b. Risk probability and risk impact

c. Risk maintenance and risk impact

d. Risk development and risk impact

34. When two numbers are added in excess-3 code and the sum is less than 9, then in order to get the correct answer it is necessary to

a. Subtract 0011 from the sum

b. Add 0011 to the sum

c. Subtract 0110 from the sum

d. Add 0110 to the sum

35. The subnet mask for a particular network is Which of the following pairs of ip addresses could belong to this network?

a. and

b. and

c. and

d. and

36. Consider the following Boolean function of four variables f(w, x, y, z)= ∑(1, 3, 4, 6, 9, 11, 12, 14). The function is

a. Independent of one variable

b. Independent of two variables

c. Independent of three variables

d. Dependent on all the variables

37. The characteristic equation of an SR flip-flop is given by

a. Qn+1 =S + RQn

b. Qn+1 = RQn’ + S’Qn

c. Qn+1 = S’ + RQn

d. Qn+1 = S + R’Qn

38. Consider a job scheduling problem with four jobs J1, J2, J3 and J4 with corresponding deadlines: (d1,d2,d3,d4) = (4, 2, 4, 2)

Which of the following is not feasible schedule without violating any job deadline?

a. J2 J4 J1 J3

b. J4 J1 J2 J3

c. J4 J2 J1 J3

d. J4 J2 J3 J1

39. The number of digit 1 present in the binary representation of 3 X 512 + 7 X 64 + 5 X 8 + 3 is

a. 8

b. 9

c. 10

d. 12

40. 0.75 in decimal system is equivalent to _____ in the octal system

a. 0.60

b. 0.52

c. 0.54

d. 0.50

41. The TCP sliding window

a. Can be used to control the flow of information

b. Always occurs when the field value is 0

c. Always occurs when the field value is 1

d. Occurs horizontally

42. More than one word are put in one cache block to

a. Exploit the temporal locality of reference in a program

b. Exploit the spatial locality of reference in a program

c. Reduce the miss penalty

        d. None of these

43. An interrupt in which the external device supplies its address as well as the interrupt request is known as

a. Vectored interrupt

b. Maskable interrupt

c. Non maskable interrupt

d. Designated interrupt

44. A certain microprocessor requires 4.5 microseconds to respond to an interrupt. Assuming that the three interrupts I1, I2 and I3¬ require the following execution time after the interrupt is recognized:

I1 requires 25 microseconds

I2 requires 35 microseconds

I3 requires 20 microseconds

I1 has the highest priority and I3 ha the lowest priority. What is the possible range of time for I3 to be executed assuming that it may or may not occur simultaneously with other interrupts?

a. 24.5 microseconds to 39.5 microseconds

b. 24.5 microseconds to 93.5 microseconds

c. 4.5 microseconds to 24.5 microseconds

d. 29.5 microseconds to 93.5 microseconds

45. The following numbers are inserted into an empty binary search tree in given order: 10, 1, 3, 5, 15, 12, 16. What is the height of the binary search tree

a. 2

b. 3

c. 4

d. 6

46. Which of the following architecture is/are not suitable for realising SIMD?

a. Vector processor

b. Array processor

c. Von Neumann

d. All of the above

47. Rapid configurations of disks are used to provide

a. Fault tolerance

b. High speed

c. High data density

d. None of these

48. Which of the following need not necessarily be saved on a context switch between processes?

a. General purpose register

b. Translation lookaside buffer

c. Program counter

d. All of these

49. A public key encryption system

a. Allows anyone to decode the transmission

b. Allows only the correct sender to decode the data

c. Allows only the correct receiver to decode the data

d. Does not encode the data before transmitting it

50. Consider the logical address space of 8 pages of 1024 words mapped into memory of 32 frames. How many bits are there in the logical address?

a. 13 bits

b. 15 bits

c. 14 bits

d. 12 bits

51. Which of the following statement is wrong?

I. 2-phase locking protocol suffer from dead lock

II. Time stamp protocol suffer from more aborts

III. The block hole in DFD is a data store with only inbound flows

IV. Multivalued dependency among attribute is check at 3NF level

V. An entity-relationship diagram is a tool to represent event model

a. I, II, II

b. II, III, IV

c. III, IV, V

d. II, IV,V

52. In case of Bus/Tree topology signal balancing issue is overcome by

a. Modulation

b. Polling

c. Segmentation

d. Strong transmitter

53. A semaphore count of negative n means(s = -n) that the queue contains ¬¬_____ waiting processes

a. n + 1

b. n

c. n – 1

d. 0

54. The Black Box testing is done

a. To show that software is operational as its interfaces i.e., input and output

b. To examine internal details of code

c. At client side

d. None of the above

55. Which of the following are Assembler Directives?





a. II, III and IV

b. I, III and IV

c. III and IV

d. I, II, III and IV

56. E-commerce involves:

a. Electronic Data Interchange

b. Electronic mail

c. Electronic Bulletin Board

d. All of the above

57. Which is the correct definition of a valid process transition in an operating system?

a. Wake up: Ready -> Running

b. Dispatch: Ready -> Running

c. Block: Ready -> Running

d. Timer Run Out: Ready -> Blocked

58. Which of the following is not a software process model?

a. Linear sequential model

b. Prototyping model

c. The spiral model

d. COCOMO model

59. Theoretically, how many 1.25 Mz carrier are there in CDMA cell?

a. 18

b. 22

c. 9

d. 64

60. Banker’s algorithm is used for _____ purpose.

a. Deadlock avoidance

b. Deadlock removal

c. Deadlock prevention

d. Deadlock continuation

61. On a LAN where are IP datagrams transported?

a. In the LAN header

b. In the application field

c. In the information field of the LAN frame

d. After the TCP header

62. The Boolean theorem AB + A’C + BC = AB + A’C corresponds to

a. (A + B).(A’ + C).(B + C) = (A + B).(A’ + C)

b. AB + A’C + BC = AB +BC

c. AB + A’C + BC = (A + B).(A’ + C).(B + C)

d. (A + B).(A’ + C).(B + C) = AB + A’C

63. Four jobs to be executed on a single processor system arrive at time 0 in order A, B, C, D. Their burst CPU time requirements are 4, 1, 8, 1 time units respectively. The completion time of A under round robin scheduling with time slice of one time unit is

a. 10

b. 4

c. 8

d. 9

64. The term “aging” refers to

a. Booting up the priority of a process in multilevel of queue without feedback

b. Gradually increasing the priority of jobs that wait in the system for a long time to remedy infinite blocking

c. Keeping track of the following a page has been in memory for the purpose of LRU replacement

d. Letting job reside in memory for a certain amount of time so that the number of pages required can be estimated accurately

65. Phase transition for each bit are used in

a. Amplitude modulation

b. Carrier modulation

c. Manchester encoding

d. NRZ encoding

66. If there are five routers and six networks in an intranet using link state routing, how many routing tables are there?

a. 1

b. 5

c. 6

d. 11

67. The output 0 and 1 level for TTL logic family is approximately

a. 0.1 and 5V

b. 0.6 and 3.5V

c. 0.9 and 1.75V

d. -1.75 and 0.9 V

68. The number of page frames that must be allocated to a running process in a virtual memory environment is determined by

a. The instruction set architecture

b. Page size

c. Number of processes in memory

d. Physical memory size

69. Armstrong’s inference rule does not determine

a. Reflexivity

b. Augmentation

c. Transitivity

d. Mutual dependency

70. BCNF is not used for cases where a relation has

a. Two or more candidate keys

b. Two candidate keys and composite

c. The candidate key overlap

d. Two mutually exclusive foreign keys

71. Which of the following is correct with respect to Two phase commit protocol

a. Ensures serializability

b. Prevents deadlock

c. Detects deadlock

d. Recover from deadlock

72. An e-mail contains a textual birthday greeting, a picture of a cake, and a song. The order is not important. What is the content type?

a. Multipart / mixed

b. Multipart / parallel

c. Multipart / digest

d. Multipart / alternative

73. The range of IP addresses from to are

a. Reserved for loopback

b. Reserved for broadcast

c. Used for multicast packeting

d. Reserved for future addressing

74. SHA-1 is a

a. Encryption algorithm

b. Decryption algorithm

c. Key exchange algorithm

d. Message digest function

75. The correct matching for the following pairs is

i. Disk check                   1. Round robin

ii. Batch processing          2. Scan

iii. Time sharing                3. LIFO

iv. Stack operation            4. FIFO

             A        B       C       D

a.   3         4        2       1

b.   4         3        2       1

c.   3         4        1       2

d.   2         4        1       3

76. The process of organising the memory into two banks to allow 8- and 16- bit data operation is called

a. Bank switching

b. Indexed mapping

c. Two way memory interleaving

d. Memory segmentation

77. A one dimensional array has A has 1 . . . 75. Each element is a string and takes up three memory words the array is stored at location 1120 decimal. The starting address of A[49] is

a. 1267

b. 1164

c. 1264

d. 1169

78. The expression 1 * 2 ^ 3* 4 ^ 5 * 6 will be evaluated as

a. 3230

b. 16230

c. 49152

d. 173458

79. A full binary tree with n leaves contain

a. n nodes

b. log2 n nodes

c. 2n – 1

d. 2n nodes

80. The use of multiple register windows with overlap causes a reduction in the number of memory accesses for

i. Function locals and paramete


ii. Register saves and restores

iii. Instruction fetches

a. 1 only

b. 2 only

c. 3 only

d. 1, 2 and 3

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7 Responses to ISRO Sample Paper for Research Program


    explanation about full adder and full subtractor using circuit diagrams

  2. Niks says:

    can you please please give the solutions of the above given questions ??
    its urgent !!

  3. Tapash Mazumder says:

    Indian Space Research Organisation (ISRO) , a very highly honoured institute . Brilliant work in preparing such a sample paper

  4. RANJIT SINGH says:

    This sample paper is very helpful for a student who is aiming to work in ISRO.

  5. Kishlay Verma says:

    Really a nice collection of questions. Being in ISRO is a dream for almost everyone who is interested in Research works. Here is a help for fulfilling their dream and they must utilize it.

  6. Sounak Ghosh says:

    ISRO is the primary space agency of the Indian government.This post consists of a brilliant sample paper which is technically designed with the same marking schemes and difficulty similar to the exam.It will really be very helpful for the students….

  7. Amit Kumar says:

    ISRO is a very good institute to research and higher study. This sample paper gives the basic idea of question pattern and questions standard.

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