CSSC-AVADI CLUSTER – ZONE 9
PRE-BOARD EXAMINATION
Class-12
(Computer Science -083)
MARKING SCHEME
Marks
Q. Question
No
SECTION - A
1. False
1
1
2. d. degree=18 cardinality=28
1
3. d.34
1
4. a. [4, 5, 'Good', 6, 7, [8, 9, 'Food', 11]]
1
5. d. ID
6. b. PAN 1
7. a. 1 1
2
3
8. c. Uie ttso mrc 1
9. b. Statement 4 1
10. c. Em@x @aC@ 1
11. bandwidth 1
12. d. global x 1
13. True 1
14. d. Update table command is used to create table in a database. 1
15. circuit 1
16. c. dump( ) 1
17. a) 1
1 OF 7
18. c) 1
SECTION B
19. (i) File Transfer Protocol ½ mark
for each
Transmission Control Protocol abbreviati
on.
(ii) Hub is a networking device used to connect multiple computers and
broadcast the message to all computers connected to it. 1 mark for
hub
A switch is used to connect multiple computers in a network but switch is 1 mark for
an intelligent hub as it transfers message only to the intended computer. switch
OR
1 mark for
(i) A web server is a program that runs on a computer connected to the correct
internet. It is a server that stores web pages and responds to the requests answer
made by web browser. 1 mark for
difference
(ii) https (Hyper Text Transfer Protocol Secure) is the protocol that uses
SSL (Secure Socket Layer) to encrypt data being transmitted over the
Internet. Therefore, https helps in secure browsing while http does not.
20. Value=30 Each error
for VAL in range(0,Value): #error 1 colon to be added ½ mark
if VAL%4==0: #error 2 VAL
print(VAL*4)
elif VAL%5==0: #error 3 elseif to be changed
print(VAL+3)
else:
print(VAL+10) #error 4 print
21. def lenFOURword(L):
ndexList=[]
for i in range(len(L)):
if len(L[i])==4:
indexList.append(i)
return indexList
½ mark for function header
½ mark for loop
½ mark for checking condition
½ mark for appending
OR
def modilst(L):
for i in range(len(L)):
if L[i] % 5 == 0:
L[i]+=10
L = [12,10,15,20,25]
modilst(L)
print(L)
½ mark to deducted for each syntax error. Marks to be awarded for a
different logic. 1 mark to be deducted if the function call is not written
2 OF 7
22. {2: 3, 4: 3, 1: 2, 3: 2} 2 mark
23. def delbook(L1, titke): 1 mark for
L1.remove(title) each line
Or
import math
function sqrt()
24 ALTER TABLE EMP ADD bonus integer; 1 mark for
alter and 1
Or for add.
Select * from employee order by DOJ DESC; 1 m for
each query
Select * FROM EMPLOYEE WHERE DOJ between ‘2006-02-09’ and
‘2009-08-02’;
25. 1m for
each line
SECTION C
26. SELCcME&cs 3 mark for
correct
output
27. 1 mark for
i) and ii)
output
½ for iii)
and iv)
3 OF 7
28. 1 mark for
open and
close files
½ mark
for reading
data
1 mark for
loop and if
OR statement
½ mark
for
displaying
data
29. (a) Degree – 6 Cardinality – 6 1 mark for
each
b) UPDATE inventory SET stock=stock+10 WHERE company = 'Parley';
c) DELETE FROM inventory WHERE RATING IS NULL;
30. data={'India':140, 'USA':50, 'Russia':25, 'Japan':10} ½ mark
should be
stack=[]
deducted
def push(stack, data): for all
incorrect
for x in data:
syntax
if data[x]>25:
stack.append(x)
push(stack, data)
print(stack)
Full marks to be awarded for any other logic that produces the correct
result.
SECTION D
31. i) Select cname from company, customer where 1 mark for
company.CID=customer.CID; each query
ii) Select cname from company order by cname desc;
iii) Update customer set price=price+1000 where name like ‘%S’;
iv) Select productname, city from company;
32. import csv ½ mark
def ADD(): for
4 OF 7
with open('furniture.csv','a',newline='') as f: importing
fid=input("Enter furniture ID: ") module
desc=input("Enter Description: ") ½ for
pr=input("Enter Price: ") function
disc=input("Enter discount: ") definition
rec=[fid,desc,pr,disc] 1 for
w=csv.writer(f) getting
w.writerow(rec) data
1 for
import csv writer
def COUNTR(): 1 for
with open('furniture.csv') as f: writerow
r=csv.reader(f)
c=0
for rec in r: ½ mark
if eval(rec[2])<5000: for
c+=1 importing
print("Number of such records =",c) module
½ for
function
definition
1 for
reader
function
1 for loop
1 for if
SECTION E
33 (i) TTC should install its server in finance block as it is having maximum 1 for each
correct
number of computers.
answer
(ii) Any suitable layout
(iii) Satellite Link.
(iv) Switch.
(v) LAN
34. A binary file can be managed only by some specific applications/program 1 mark for
whereas a csv file can be managed using multiple general purpose each
applications/programs correct
def ADD(): difference
with open('furniture.dat','ab') as f: (
fid=input("Enter furniture ID: ") minimum
desc=input("Enter Description: ") two
pr=eval(input("Enter Price: ")) difference
disc=eval(input("Enter discount: ")) s should
rec=[fid,desc,pr,disc] be given)
pickle.dump(rec,f) ½ mark
def COUNTR(): for
with open('furniture.dat','rb') as f: correctly
c=0 opening
try: and
5 OF 7
while True: closing
rec=pickle.load(f) files
if rec[2]<5000: ½ mark
c+=1 for correct
except: try and
pass except
print("Number of such records =",c) block ½
OR mark for
correct
Text files: loop 1
• Extension is .txt mark for
• Data is stored in ASCII format that is human readable correctly
• Has EOL character that terminates each line of data stored in the text files copying
Binary Files data
• Extension is .dat
• Data is stored in binary form (0s and 1s), that is not human readable. ½ mark
for correct
return
statement
½ mark
for
correctly
opening
and
closing
files ½
mark for
correct try
and except
Note: Any other correct logic may be marked block ½
mark for
correct
loop ½
mark for
correct if
statement
1 mark for
correctly
displaying
data
35. (i) Elimination of data redundancy, sharing data, (relevant answer) 1 marks
(ii) import mysql.connector as ctor for
dbcon=ctor.connect(host=”localhost”,user=”learner”,password=”fast”,datab advantage
ase=’items’) s
cursor=dbcon.cursor() 1m for
sql1=”delete from category where name=’%s’” import
data1=(‘Stockable”) 1 for
cursor.execute(sql1,data1) connection
dbcon.commit() obj
print(“Rows affected:”,cursor.rowcount) ½ for
dbcon.close() cursor
½ for
6 OF 7
OR query
i) All keys that have the properties to become a primary key are candidate ½ for
keys. The candidate keys that do not become primary keys are alternate execute
keys. ½ for
commit
ii) import mysql.connector as sqltor
mycon=sqltor.connect(host=”localhost”<USER+”learner”,password=”fast”,
database=”test”) 1m for (i)
cursor=mycon.cursor() 1m for
cursor.execute(“select * from student”) import
data=cursor.fetchmany(3) 1 for
count=cursor.rowcount connection
for row in data: obj
print(row) ½ for
mycon.close() cursor
½ for
query
½ for
execute
½ for loop
End of Paper
7 OF 7
