Unwanted energy from source other than the transmitter.
Attenuation
Distortion
Delay
Noise
Correct Answer :
D. Noise
Related Questions
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.
The maximum number of children in a B-tree of order m is
m+1
m
m-1
m/2
Related fields in a database are grouped to form a
data file.
data record.
menu.
bank.
A relation that has no partial dependencies is in which normal form
First
Second
Third
BCNF
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
The statement
Every foreign-key value must match a primary-key value in an associated table
Is related to
View
Cursor defination
Referential intergrity
Trigger
Which of the following is not a database object?
index
sequence
cursor
trigger
Data stored in cursor is called ……………
record
active data set
object
none of the above
Referential integrity
controls relationships between operations of an object
controls relationships between instances of a class
controls relationships between attributes in a table
controls relationships between tables in a database
An association of several structure of a data base can be expressed graphically by?
Tuple
Record
Relationship
Field
Tape storage is referred to as
sequential access storage
direct access storage
random access storage
none of the above
The mode in which data item may be locked
Partner
Mutual
Exclusive
Atomic
The index table has …… Columns.
1
2
3
4
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
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
Cross Product is a:
Unary Operator
Binary Operator
Ternary Operator
none of the above
The host part in a class A type of an IP address has
12 bits
16 bits
24 bits
28 bits
Disk storage is referred to as
sequential access storage
direct access storage
random access storage
none of the above
The access protocol used by traditional Ethernet
CSMA/CA
CSMA/CD
CSMA
Token ring
What does a field or a combination of fields that has a unique value called ?
Foreign key
Secondary key
Primary key
Alternate key
Mail services are available to network users through the
Session layer
Presentation layer
Application layer
Transport layer
Consider the join of a relation R with relation S. If R has m tuples and S has n tuples,
then the maximum size of join is:
mn
m+n
m+n)/2
2 m+n)
What is the result of the following SQL statement ?
SELECT A.emp_Name, B.ph_num
FROM emp A LEFT OUTER JOIN phone B
ON A. emp_ID = B.emp_ID
A list of employees phone number
A list of all employees that have spouses, with phone number included in the list
A list of all employees names, including the phone number if they have one
Two lists : One list of employees, the other of phone numbers
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
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
It is possible to define a schema completely using
VDL and DDL.
DDL and DML.
SDL and DDL.
VDL and DML.
Which one of the following is provided by a data dictionary ?
User data
Database structure data
Sorted data
Functional data
The number of cursors depend on the
number of queries
number of attributes
size of memory area
none of these
Noiseless channel has ……… types of protocols.
2
3
4
5
Range variables are designed using the
TO clause
FROM clause
RANGE clause
none of the above