Attenuation can be also expressed in decibel dB) and commonly used because.
i) Signal strengths often fall off logarithmically
ii) Cascade losses and gains can be calculated with simple additions and subtractions
i only
ii only
Both A and B
None of the above
Correct Answer :
C. Both A and B
Related Questions
A subschema expresses
the logical view.
the physical view.
the external view.
all of the above.
Which of the following works as a filter?
UPDATE
DROP
ALTER
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
Aggregate functions are also called
serial functions
non-serial functions
row functions
column functions
File organization that provides fast access to any arbitrary record
Hashed file
B-tree
Ordered file
Unordered file
Specialization is a
top-down approach.
bottom-up approach.
left-right approach.
none of the above
Electromagnetic spectrum included in radiowaves are
i) Super High Frequency (SHF)
ii) Very High Frequency (VHF)
iii) Ultra High Frequency (UHF)
iv) High Frequencies (HF)
i, ii and iii only
i, ii and iv only
ii, iii and iv only
i, iii and iv only
In which of the random-access method, stations do not sense the medium?
ALOHA
ETHERNET
CSMA/CA
CSMA/CD
The host part in a class A type of an IP address has
12 bits
16 bits
24 bits
28 bits
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
View never contains derived columns.
True
False
Cant say
none
Which of the following are the properties of entities?
Groups
Table
Attributes
Switchboards
Data independence means
data is defined separately and not included in programs.
programs are not dependent on the physical attributes of data.
programs are not dependent on the logical attributes of data.
both B) and C).
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
For large networks, _______ topology is used
Ring
Bus
Mesh
none of these
Object based data models are used in describing the abstraction of the following levels?
Conceptual and view
Only physical
Physical and conceptual
Only conceptual
Full form of CIDR
Classful Inter Domain Routing
Classless International Domain Routing
Classless Inter Domain Routing
none of these
It is possible to define a schema completely using
VDL and DDL.
DDL and DML.
SDL and DDL.
VDL and DML.
A relation which is in 3NF is
in 1NF also
in 2NF also
free from transitive dependencies
All of these
The physical path over which a message travels
Thermal
Medium
Protocol
Impulse
The degree of the table with 500 rows and 7 columns is
500
7
3500
none of these
What are the different types of radio waves that are used for computer network applications?
i) Spread spectrum
ii) High power, single frequency
iii) High power, multiple frequency
iv) Low power, single frequency
v) Low power, multiple frequency
i, ii and iii only
i, ii and iv only
ii, iii and iv only
i, iii and iv only
Commit operation …………… writes the changes made to the database.
temporarily
permanently
none of these
all of the above
Which of the following statements is not true about two tier client server database architecture?
SQL statements are processed on tier server
SQL statements may be processed on some of the clients
Business logic is mostly processed on clients
Business logic may be processed on the server
DECLARE is a(an)
executable statement.
declarative statement.
Ordered file
none of the above
A transaction has following states
i) Active
ii) Fail
iii) Abort
iv) Commit
i and ii only
ii and iii only
i and iii only
iii and iv only
The union of primary keys of a related entity becomes …………. Of a relation.
primarykey
superkey
candidatekey
foreignkey
The mode in which data item may be locked
Partner
Mutual
Exclusive
Atomic
which of the following is a binary operation?
project
select
rename
none of the above
In an Entity-Relationship Diagram Diamonds represents
Attributes
Multi-valued attributes
Weak entity set
Relationship sets