PREVIOUS YEAR SOLVED PAPERS - November 2017 Paper 3

Avatto > > UGC NET COMPUTER SCIENCE > > PREVIOUS YEAR SOLVED PAPERS > > November 2017 Paper 3

11. Given two relations R1(A, B) and R2(C, D), the result of following query
Select distinct A, B
from R1, R2
is guaranteed to be same as R1 provided one of the following condition is satisfied.

  • Option : B
  • Explanation : Select A,B From R1, R2 : In this query first we will take cartesian product of R1, R2 (R2 must be non empty)for this 0- R2 then select distinct A,B from cartesian product of R1, R2 (for A,B being distinct there should not any duplicate A,B). And Select A,B From R2 For this query A,B → No duplicate A,B. By combining condition for both query we will get the right condition. So, option (B) is correct.
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12. Consider a schema R(A, B, C, D) and following functional dependencies.
A → B
B → C
C → D
D → B
Then decomposition of R into R1 (A, B), R2(B, C) and R3(B, D) is __________ .

  • Option : A
  • Explanation :
    Schema R(A, B, C, D) is decomposed into three relation → R1 (A, B), R2(B, C) and R3(B, D) Now dependecies derived from R1 (A, B) are: A → B B → C but C is not attribute here in this relation. Dependencies derived from R1 (B, C) are: B → C C → D D is not the attribute in relation. Dependecies derived from R1 (B, D) are: D → B B → C C → D All the dependecies are preserved and it is a lossless decomposition. So, option (A) is correct.
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13. Which of the following is not a component of Memory tube display ?

  • Option : D
  • Explanation :
    Main components of memory tube display are:
    1. Flood gun
    2. Primary gun
    3. Writing Beam
    4. Collector
    5. Storage grid
    6. Screen
    7. Focussing & deflection system
    8. Flood electron
    9. Ground or base
    Only Liquid crystal is not enlisted here and it is not the display component in memory tube. So, option (D) is correct.
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14. Which of the following is not true in case of Oblique Projections?

  • Option : D
  • Explanation :
    >Option (A) → Parallel projection rays are not perpendicular to the viewing plane. TRUE Option (B) → Parallel lines in space appear parallel on the final projected image. TRUE Option (C) → Used exclusively for pictorial purposes rather than formal working drawings. TRUE Option (D) → Projectors are always perpendicular to the plane of projection. False So, option (D) is correct.
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Related Quiz.
November 2017 Paper 3