Thermal noise is often referred to as ............... noise, because it affects uniformly the different frequencies.
Gray
White
Blue
Black
Correct Answer :
B. White
Related Questions
Which of the following is not a database object?
index
sequence
cursor
trigger
Unwanted energy from source other than the transmitter.
Attenuation
Distortion
Delay
Noise
Select the incorrect statement
View is derived from other tables.
Once a transaction has executed commit work its effect cant be undone by rollback work .
The input to the aggregate function avg can be non numeric data types
A primary key can never be null.
QBE
Query By Execution
Query By Example
Query By Extraction
None of the above.
Select the incorrect statement
BCNF is stronger than 3NF
Relational algebra is a non-procedural language
Every conflict serializable schedule is view serializable.
none of the above
In two-phase locking protocol the two phases are
growing phase and shrinking phase
execution phase and blocking phase.
running phase and sleeping phase.
none of the above
Which command is used to cancel privileges granted through the GRANT command ?
CANCEL
OVER
STOP
REVOKE
A DBMS query language is designed to
support end users who use English-like commands.
support in the development of complex applications software.
specify the structure of a database.
all of the above.
For large networks, _______ topology is used
Ring
Bus
Mesh
none of these
Commit operation …………… writes the changes made to the database.
temporarily
permanently
none of these
all of the above
The exists construct returns the value true, if the argument subquery is
empty
nonempty
contains null values
none of the above
A subschema expresses
the logical view.
the physical view.
the external view.
all of the above.
UML is stands for
Universal Modeling Language
Unified Modeling Language
United Modeling Language
Uni Modeling Language
A relation is said to be in ………. If it doesnt contain partial dependency
1NF
2NF
3NF
BCNF
Select the incorrect statement(s)
i) Shared locks are compatible with each other.
ii) A relation which is in 3NF may have redundancy due to composite keys.
iii) A table in a database can have multiple indexes.
i only
ii, only
ii, iii only
none of the above
The ________ states that a foreign key must either match a primary key value in another relation or it must be null.
entity integrity rule
referential integrity constraint
composite attribute
action assertion
State which of the following statements are True
i) TCP is connection oriented but unreliable
ii) UDP is connection oriented but unreliable
iii) TCP is connectionless but reliable
iv) UDP is connectionless but reliable
i and ii only
ii and iii only
i and iii only
None of these
A relation that has no partial dependencies is in which normal form
First
Second
Third
BCNF
A fragmentation is categorized in
1 part
2 part
3 part
4 part
Data stored in cursor is called ……………
record
active data set
object
none of the above
The ability to modify the conceptual schema without causing any change to the application program is known as
Physical data independence
Logical data independence
External data independence
Static data
An entity set that does not have sufficient attributes to form a primary key is a
strong entity set.
weak entity set.
simple entity set.
primary entity set.
Select the correct
i) A timestamp-based scheduler cant produce live lock
ii) Aggregate functions cant appear with HAVING clause.
iii) Isolation is a property of database transaction.
i and ii only
ii and iii only
i and iii only
i only
Select the correct statement
i) Aggregate functions work on a group of data and return a single value.
ii) ODBC connects the frontend with the database without considering its compatibility
iii) View definition cant be used at multiple places through with clause .
i and ii only
ii and iii only
i and iii only
i only
Technique used in log based recovery
Immediate database modification
Graph-based recovery
key dependencies
none of the above
In which of the random-access method, stations do not sense the medium?
ALOHA
ETHERNET
CSMA/CA
CSMA/CD
A transaction which may not complete its execution successfully is termed as
Failed
Aborted
Blocked
Finished
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
Encoding method which does not provide for synchronization
B8ZS
Manchester
RZ
NRZ-L
In which of the following SET concept is used ?
Network Model
Hierarchical Model
Relational Model
None of these