Computer Science Class XII

1. KENDRIYA VIDYALAYA NO. 2 ARMY BHUJ
PERIODIC TEST-3 (2021-22)
Class : XII Duration : 90 Min.
Sub. : COMP. SC. (Python) Max. Marks : 35
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Note – All questions are compulsory.
(1.) MultipleChoiceQuestions– [5marks]
A. Arelationaldatabaseconsists ofa collection of
(a.) Tuples (b.) Attributes (c.) Relations (d.) Keys
B. What is the full form of SMTP ?
(a.) Secure Mail Transfer Protocols
(b.) Simple Mail Transfer Protocol
(c.) Simple Meet Transaction Protocol
(d.) Noneofthese
C. ConsiderfollowingSQLcommand.Whattypeofcommandisthis?
ALTER TABLE
(a.) DML (b.) DDL (c.) DCL (d.) None of the above
D. The data type CHAR(n) and VARCHAR(n) areused to create ,and types
of string/text fields in a database.
(a.) Fixed, Equal (b.) Equal,Variable
(c.) Fixed, Variable (d.) Variable,Equal
E. ---------------------- is a device that works on the receive and broadcast method.
(a.) Modem (b.) Hub
(c.) Switch (d.) None of the above
(2.) Expand the followings: (i) VoIP (ii) SIM (iii)SSH (iv) NFC [2marks]
(3.) Identify the error in the following SQL query which is expected to delete all rows of a table TEMP
without deleting its structure and write the correct one:
DELETE TABLE TEMP; [1 marks]
(4.) Identify the Guided and Un-Guided Transmission Media out of the following:
Satellite, Twisted Pair Cable, Optical Fiber, Infra-Red waves
5.) Definetheseterms(withexample)– [2marks]
(a.) PrimaryKey (b.) Foreign key
(6.) DifferentiatebetweenDDLandDMLcommands.Write02commandsforeachtype. [2marks]
(7.) Write the name of topology in which all the nodes are connected through a single path cable.
[1 mark]
(8.) Write command to list the available databases in MySQL? [1 mark]
(9.) Write SQL statement to create the following table (with given constraints) – [3marks]

2. Table- Album
Field Name Data Type Data Limit Constraint
Album_id Integer 4 PRIMARY KEY
Album Text 20 NOT NULL
Cost Integer (5)
Qty Integer 3 DEFAULT 0
Album_no Integer UNIQUE
Discount Numeric (4)
(10.) In a existingtableEMPLOYEEwritecommandfor these– [3marks]
a.) add a column named SPECIAL PAY of data type INT(5) and with a DEFAULT value of
2400.
b.) Modifycolumn JOB to havenew widthof 30 characters.
c.) RemovetheJOB_IDcolumnoftheEMPLOYEEtable.
(11.) ConsiderthefollowingCLUBtableandwriteSQLqueriesfrom(a)to(e) [6marks]
Table: CLUB
COACH_ID COACHNAME AGE SPORTS DATOFAPP PAY SEX
1 KUKREJA 35 KARATE 27/03/1996 1000 M
2 RAVINA 34 KARATE 20/01/1998 1200 F
3 KARAN 34 SQUASH 19/02/1998 2000 M
4 TARUN 33 BASKETBALL 01/01/1998 1500 M
5 ZUBIN 36 SWIMMING 12/01/1998 750 M
6 KETAKI 36 SWIMMING 24/02/1998 800 F
7 ANKITA 39 SQUASH 20/02/1998 2200 F
8 ZAREEN 37 KARATE 22/02/1998 1100 F
9 KUSH 41 SWIMMING 13/01/1998 NULL M
10 SHAILYA 37 BASKETBALL 19/02/1998 1700 M
(a.)Toshow all theinformationabout theswimmingcoaches intheclub .
(b.)Tolistnamesofallcoacheswiththeirdateofappointment(DATOFAPP)indescendingorder.
(c.) To display a report , showing coachname , pay ,age and bonus (15% of pay) for all the
coaches.[ the name of the field 15% of payshould be ‘Bonus’ ]
(d.)Todisplaytotalno.ofmaleandfemalecoachesindividually.
(e.)To displaydetail of the coachesindescending order based coachname.
(f.) Todisplaycoachnameinwhichnamecontains2nd characteras‘A’.
(12.) Writeoutput of thefollowingSQLqueries basedon abovementioned CLUBtable. [4marks]
(a.)SELECT COUNT(pay) FROM club ;
(b.)SELECT coachname, datofapp FROM CLUB WHERE Sports= “Karate” and Sex=”F” ;
(c.) SELECT AVG(age) “AVERAGE AGE” FROM club.
(d.)SELECTCOUNT(*)FROMclubGROUPBYSEX;

3. (13.)Rehaana Medicos Center has set up its new center in Dubai. It has four buildings as shown in the
diagram given below: [5Marks]
As a network expert, provide the best possible answer for the following queries:
i) Suggest a cable layout of connections between the buildings.
ii) Suggest the most suitable place (i.e. buildings) to house the server of this organization.
iii) Suggest the placement of the following device with justification: a) Repeater b) Hub/Switch
iv) Suggest a system (hardware/software) to prevent unauthorized access to or from the network.
v) Which cable is best suited for above layout.