Radio frequencies below ............. are more suitable for omnidirectional applications.
300MHz
1GHz
5GHz
10 GHz
Correct Answer :
B. 1GHz
Related Questions
The access protocol used by traditional Ethernet
CSMA/CA
CSMA/CD
CSMA
Token ring
In two-phase locking
the data items are locked in growing phase.
the data items are released in shrinking phase.
Both A and B are true
Both A and B are false
View never contains derived columns.
True
False
Cant say
none
The mode in which data item may be locked
Partner
Mutual
Exclusive
Atomic
The privilege lists include
i) select
ii) insert
iii) update
iv) delete
only i)
only i) ii)
only i) ii) iii)
i) ii) iii) iv)
In an Entity-Relationship Diagram Diamonds represents
Attributes
Multi-valued attributes
Weak entity set
Relationship sets
Which of the following will NOT eliminates the ambiguities of a null value?
Define the attribute as required
Define subtypes
Define each attribute as having an initial value that is recognized as blank
Define supertypes
Data stored in cursor is called ……………
record
active data set
object
none of the above
Encoding method which does not provide for synchronization
B8ZS
Manchester
RZ
NRZ-L
The transaction consists of all statements executed between
the begin transaction and end transaction
the start transaction and end transaction
the begin transaction and finish transaction
none 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
The number of cursors depend on the
number of queries
number of attributes
size of memory area
none of these
UML is stands for
Universal Modeling Language
Unified Modeling Language
United Modeling Language
Uni Modeling Language
RAID
Redundant Arrays of Independent Disks
Redundant Arrays of Independent Drives
Redundant Arrays of Interconnected Drives
Redundant Arrays of Interconnected Disks
In an object oriented model, one object can access data of another object by passing?
Instance variable
Variable
Message
Function
A data manipulation command the combines the records from one or more tables is called
SELECT
PROJECT
JOIN
PRODUCT
A …………… is a memory area where data are processed.
view
trigger
cursor
none of the above
What does the number of attributes in a relation is called?
Cardinality
Degree
Tuple
Order
Select the incorrect statement(s)
i) Foreign key values can be left blank
ii) In SQL duplicates may be present
iii) Theta join operation doesnt remove duplicate columns.
iv) NULL value means string of blank characters.
i ,iii only
ii, iv only
iii, iv only
ii, iii, iv
FDDI protocol operates in
i) Transport layer
ii) Network layer
iii) Datalink layer
iv) Physical layer
i and ii only
ii and iii only
i and iii only
iii and iv only
In an Entity-Relationship Diagram Ellipses represents
Attributes
Weak entity set
Relationship sets
Multi-valued attributes
Expand the acronym OLAP
Object Linked Access Program
Organizational Architecture Processing
Online Analytical Processing
none of these
What is the max data capacity of STP?
1 Gbps
56 Mbps
100 Mbps
256 Mbps
Database locking concept is used to solve the problem of
Lost Update
Uncommitted Dependency
Inconsistent Data
All of the above
A relation that has no partial dependencies is in which normal form
First
Second
Third
BCNF
If the .................... is too much, the receiver may not be able to detect the signal at all or the signal may fall below the noise level.
Noise
Delay
Dispersion
Attenuation
Specialization is a
top-down approach.
bottom-up approach.
left-right approach.
none of the above
A transaction is said to have terminated if it has
either committed or aborted
either partially committed or aborted
either committed or failed
none of these
The host part in a class A type of an IP address has
12 bits
16 bits
24 bits
28 bits
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