System Analysis and Design

181. A data flow can

  1. only emanate from an external entity
  2. only terminate in an external entity
  3. may emanate and terminate in an external entity
  4. may either emanate or terminate in an external entity but not both
Correct answer: (C)
may emanate and terminate in an external entity

182. Data cannot flow between two data stores because

  1. it is not allowed in a DFD
  2. a data store is a passive repository of data
  3. data can get corrupted
  4. they will get merged
Correct answer: (D)
they will get merged

183. A DFD is normally levelled as

  1. it is a good idea in design
  2. it is recommended by many experts
  3. it is easy to do it
  4. it is easier to read and understand a number of smaller DFDs than one large
Correct answer: (D)
it is easier to read and understand a number of smaller DFDs than one large

184. When a process is expanded during levelling

  1. data flows entering it are replaced
  2. all data stores used by it are replaced
  3. all data flows entering it must also enter the levelled DFD
  4. all external entities used by it are replaced
Correct answer: (C)
all data flows entering it must also enter the levelled DFD

185. A rectangle in a DFD represents

  1. a process
  2. a data store
  3. an external entity
  4. an input unit
Correct answer: (C)
an external entity

186. Data cannot flow from an external entity to an external entity because

  1. it will get corrupted
  2. it is not allowed in DFD
  3. an external entity has no mechanism to read or write
  4. both are outside the context of the system
Correct answer: (D)
both are outside the context of the system

187. A DFD is levelled by

  1. examining complex processes in a DFD and expanding them into new DFDs with more processes which are easy to understand
  2. merging a number of simple processes in a DFD into a complex processes in a new DFD
  3. expanding the functions of a number of external entities into simpler functions
  4. splitting a number of data flows into simpler data flows
Correct answer: (A)
examining complex processes in a DFD and expanding them into new DFDs with more processes which are easy to understand

188. A physical DFD specifies

  1. what processes will be used
  2. who generates data and who processes it
  3. what each person in an organization does
  4. which data will be generated
Correct answer: (B)
who generates data and who processes it

189. By an external entity we mean a

  1. unit outside the system being designed which can be controlled by an analyst
  2. unit outside the system whose behavior is independent of the system being designed
  3. a unit external to the system being designed
  4. a unit which is not part of a DFD
Correct answer: (C)
a unit external to the system being designed

190. Data flow in a DFD must have

  1. an arrow showing direction of flow of data
  2. a meaningful name
  3. a label such as: xyz
  4. no arrows as they are confusing
  1. i and iii
  2. ii and iv
  3. iii and iv
  4. i and ii
Correct answer: (D)
i and ii
Previous
Page 19 of 61
Next