.................. occurs due to velocity of propagation the frequency varies. Thus various frequency components of a signal arrive at the receiver at different times.
Noise
Delay distortion
Attenuation distortion
Dispersion
Correct Answer :
B. Delay distortion
Related Questions
The exists construct returns the value true, if the argument subquery is
empty
nonempty
contains null values
none of the above
Multivalued dependency is removed in
4 NF
3 NF
2 NF
1 NF
Which of the following is not proper state of transaction ?
Partially aborted
Partially committed
Aborted
Committed
Query processing is
converting data to insert in a database
translation of query to lower form
range of activities involved in extracting data from a database
none of the above
The maximum number of children in a B-tree of order m is
m+1
m
m-1
m/2
Database locking concept is used to solve the problem of
Lost Update
Uncommitted Dependency
Inconsistent Data
All of the above
Object based data models are used in describing the abstraction of the following levels?
Conceptual and view
Only physical
Physical and conceptual
Only conceptual
DECLARE is a(an)
executable statement.
declarative statement.
Ordered file
none of the above
An advantage of the database management approach is
data is dependent on programs.
data redundancy increases.
data is integrated and can be accessed by multiple programs.
none of the above.
Generalization is a
top-down approach.
bottom-up approach.
left-right approach.
none of the above
Triggers are also called
active rules
passive rules
inferences
none of the above
In defining the notion of the tuple variable, which one of the clause is useful?
as
by
from
none of the above
Which of the following operator preserves unmatched rows of the relations being joined?
Inner join
Outer join
union
Intersect
Data fragmentation is performed by the …… and each fragment is stored at…………..
DBMS, same site
OS ,same site
DBMS ,different site
OS ,different site
The physical location of a record is determined by a mathematical formula that transforms
a file key into a record location is :
B-Tree File
Hashed File
Indexed File
Sequential file.
A ………… clause permits a view definition to be used in multiple places within a query.
where
exist
with
select
Which of the following is true statement ?
SQL permits attribute names to be repeated in the same relation.
a SQL query automatically eliminates duplicates.
a SQL query will not work if there are no indexes on the relations
None of these
Which topology requires a central controller or hub?
Ring
Tree
Switch
Graph
Usenet is also known as
Newsgroups
10Km to 1Km
10^3Km to 100Km
100M to 10M
Technique(s) used for data recovery after any failure
Logging
Recovery manager
Both A and B are true
Both A and B are false
Which of the following is also known as Offline storage ?
primary storage
secondary storage
tertiary storage
none of the above
Unwanted energy from source other than the transmitter.
Attenuation
Distortion
Delay
Noise
The union of primary keys of a related entity becomes …………. Of a relation.
primarykey
superkey
candidatekey
foreignkey
The database environment has all of the following components except:
users.
separate files.
database.
database administrator.
DBMS helps achieve
Data independence
Centralized control of data
Neither A) nor B)
both A) and B)
Functional dependencies are generalization of
Relation dependencies
Data dependencies
key dependencies
none of the above
Extended Entity Relationship model consists of which of the following
i) Specialization
ii) Generalization
iii) Categorization
i and ii only
ii and iii only
i and iii only
All i, ii iii
By default a user who has been granted some form of authorization
is allowed to pass them to others
is not allowed to pass them to others
may be or may not be allowed to pass them to others
none
which of the following is a binary operation?
project
select
rename
none of the above
The left outer join takes all tuples
in the left relation which didnt match with any tuple in right relation
in the left relation which matched with a tuple in right relation
in the right relation which didnt match with any tuple in left relation
in the right relation which matched with a tuple in left relation