Students can access the CBSE Sample Papers for Class 12 Computer Science with Solutions and marking scheme Term 2 Set 2 will help students in understanding the difficulty level of the exam.
CBSE Sample Papers for Class 12 Computer Science Term 2 Set 2 with Solutions
Time: 2 Hours
Maximum Marks: 35
General Instructions:
- The question paper is divided into 3 sections – A, B and C
- Section A, consists of 7 questions (1 – 7). Each question carries 2 marks.
- Section B, consists of 3 questions (8 – 10). Each question carries 3 marks.
- Section C, consists of 3 questions (11 – 13). Each question carries 4 marks.
- Internal choices have been given for question numbers 7, 8 and 12.
Section – A
(2 Marks Each)
Question 1.
Write the types of operations used in stack.
Answer:
There are two types of operations in Stack:
- Push- To add data into the stack.
- Pop- To remove data from the stack.
Question 2.
(a) Expand the following:
(i) GSM
(ii) GPRS
Answer:
- GSM: Global System for Mobile communication.
- GPRS: General Packet Radio Service.
(b) Which type of network out of LAN, PAN and MAN is formed, when you connect two mobiles using Bluetooth to transfer a video?
Answer:
PAN (Personal Area Network)
Question 3.
Differentiate between Cardinality and Degree of a table with the help of an example.
Answer:
Cardinality is defined as the number of rows in a table. Degree is the number of columns in a table.
e.g. consider the following table
| Cno | Cname |
| A101 | Rahul |
| A102 | Riya |
| A103 | Darsh |
Cardinality: 3 Degree: 2
Question 4.
db = MySQLdb.connect(‘localhost’ , ‘LibMan’, ‘isspwd’, ‘Library’)
(a) What is “Library” in the statement?
Answer:
(a) Database name
(b) What is the use of connect()?
Answer:
connect() function is used to connect or establish a connection with My SQL database.
Question 5.
Write the output of the queries (a) to (d) based on the table, Grocery given below:
Table: Grocery
| Pr_Code | Pr_Name | PrJPrice | Pr_Manufac |
| P101 | Toothpaste | 99 | Dantkanti |
| PI 02 | Soap | 20 | Lux |
| P103 | Soap | 25 | Breeze |
| P104 | Detergent | 199 | Surf Excel |
| PI 05 | Shampoo | 345 | Loreal |
(a) SELECT Pr_Name, Avg(Pr_Price) FROM Grocery Group BY Pr_Name;
Answer:
| Pr_Code | Avg (Pr_Price) |
| P101 | 199.00 |
| PI 02 | 345.00 |
| P103 | 22.50 |
| P104 | 99.00 |
(b) SELECT DISTINCT Pr_Manufac FROM Grocery;
Answer:
| Pr_ Manfac |
| Dantikanti |
| Lux |
| Breeze |
| Surf Execel |
| Loreal |
(c) SELECT COUNT(DISTINCT Pr_Name) FROM Grocery;
Answer:
4
(d) SELECT Pr_Name, MAX(Pr_Price) , MIN(Pr_Price) FROM Grocery GROUP BY Pr_ Name
Answer:
| Pr_Name | MAX(Pr_Price) | MIN(Pr_Price) |
| Detergent | 199 | 199 |
| Shampoo | 345 | 345 |
| Soap | 25 | 20 |
| Toothpaste | 99 | 99 |
Question 6.
(a) MySQL supports different character sets, which command is used to display all character sets?
Answer:
SHOW CHARACTER SET
(b) What will happen if the data being loaded into a text column exceeds the maximum size of that
type?
Answer:
Data will be truncated
Question 7.
Observe the following table and answer the parts (a) and (b):
Table: Store
| Item Code | Items | Qty | Rate |
| 10 | Gel Pen classic | 1150 | 25 |
| 11 | Sharpener | 1500 | 10 |
| 12 | Ball Pen 0.5 | 1600 | 12 |
| 13 | Eraser | 1600 | 5 |
| 15 | Ball Pen 0.25 | 800 | 20 |
(a) In the above table, can we have Qty as primary key. [Answer as Yes/No.]. Justify your answer.
Answer:
No, Because there is a duplication of values and primary key value cannot be duplicate.
(b) What is the cardinality and degree of the above table?
Answer:
Degree : 4 Cardinality : 5
OR
(a) Identify the candidate key(s) from the table store.
Answer:
Item Code and Items
(b) Consider the following table Company:
| Comp Code | Cost TJ; | Manufacturer | Item Code |
| C101 | 15 | ABC | 10 |
| C202 | 7 | ABC | 11 |
| C303 | 10 | XYZ | 12 |
| C404 | 2 | PQR | 13 |
| C505 | 12 | MNO | 15 |
Which field will be considered as the foreign key if the tables Store and Company are related in a database?
Answer:
Item Code
Section – B
( 3 Marks Each)
Question 8.
Write a function in Python PUSH (Arr), where Arr is a list of numbers. From this list push all numbers divisible by 5 into a stack implemented by using a list. Display the stack if it has at least one element, otherwise display appropriate error message.
OR
Write a function in Python POP(Arr), where Arr is a stack implemented by a list of numbers. The function returns the value deleted from the stack.
Answer:
def PUSH (Arr, value):
s = [ ]
for x in range (0, len (Arr)): if Arr [x] % 5==0:
s.append (Arr [x]) if len (s) ==0:
print (“Empty stack”) else:
print (s)
OR
def popStack (st):
if len (st) == 0:# if stack is empty print (“Underflow”) else:
l=len (st) val=st[1-1] print (val) st.pop(1-1) return val
Question 9.
(a) A table FLIGHT has 4 rows and 2 columns and another table AIRHOSTESS has 3 rows and 4 columns. How many rows and columns will be there if we obtain the Cartesian product of these two tables?
Answer: Total number of rows will be 12 and total number of columns will be 6.
(b) There is a column Salary in a Table EMPLOYEE. The following two statements are giving different outputs. What may be the possible reason?
SELECT COUNT(*) FROM EMPLOYEE;
SELECT COUNT(Salary) FROM EMPLOYEE;
Answer:
SELECT COUNT (*)
FROM EMPLOYEE:
This statement returns the number of records in the table.
SELECT COUNT(Salary)
FROM EMPLOYEE;
This statement returns the number of values (NULL values will not be counted) of the specified column.
Question 10.
Hina has created database named employee in MySQL.
She needs create table employee – Info in the database to stored various employees across the country. The data employee – Info has the follwing structure:
| FIELD NAME | DATA TYPE | REMARKS |
| Employee ID | Integer | Primary key |
| Employee Name | Varchar (255) | |
| Emergency Contact Name | Varchar (255) | |
| Phone Number | Integer | |
| Address | Varchar (255) | |
| City | Varchar (255) | |
| Country | Varchar (255) |
Help her to complete the task by suggesting appropriate SQL commands.
Answer:
CREATE DATABASE Employee;
CREATE TABLE Employee – Info
EmployeelD int primary key,
EmployeeName varchar (255),
EmergencyContactName varchar(255),
PhoneNumber int,
Address varchar (255),
City varchar (255),
Country varchar(255)
) ;
Section – C
(4 Marks Each)
Question 11.
Write SQL queries for (a) to (c) and find outputs for SQL queries (d), which are based on the tables.
Table: CUSTOMER
| CNO | CNAME | ADDRESS |
| 101 | Richa Jain | Delhi |
| 102 | Surbhi Sinha | Chennai |
| 103 | Lisa Thomas | Bengalore |
| 104 | Imran Ali | Delhi |
| 105 | Roshan Singh | Chennai |
Table: TRANSACTION
| TRNO | CNO | AMOUNT | TYPE | DOT |
| T001 | 101 | 1500 | Credit | 2017-11-23 |
| T002 | 103 | 2000 | Debit | 2017-05-12 |
| T003 | 102 | 3000 | Credit | 2017-06-10 |
| T004 | 103 | 12000 | Credit | 2017 – 09 – 12 |
| T005 | 101 | 1000 | Debit | 2017 – 09 – 05 |
(a) To display details of all transactions of TYPE Credit from table TRANSACTION.
Answer:
SELECT * FROM TRANSACTION WHERE TYPE =”Credit”;
(b) To display the CNO and AMOUNT of all Transactions done in the month of September 2017 from table TRANSACTION.
Answer:
SELECT CNO,AMOUNT FROM TRANSACTION WHERE (MONTH(DOT)=”September” AND YEAR(DOT)=2017);
(c) To display the last date of transaction (DOT) from the table TRANSACTION and customer name from CUSTOMER for the customer having CNO as 103.
Answer:
SELECT MAX(DOT), CNAME FROM TRANSACTION, CUSTOMER WHERE CNO=”103″ AND CUSTOMER.CNO=TRANSACTION.CNO:
(d) SELECT CNO, COUNT(*), MAX (AMOUNT) FROM TRANSACTION GROUP BY CNO HAVING COUNT (*)> 1;
Answer:
| CNO | MAX (AMOUNT) | COUNT(*) |
| 101 | 1500 | 2 |
| 103 | 12,000 | 2 |
Question 12.
(a) Identify the type of topology from the following:
(i) Each node is connected with the help of a single cable.
Answer:
Bus topology
(ii) Each node is connected with central switching through independent cables.
Answer:
Star topology
OR
Server side scripting : ASP, JSP
Client side scripting : JavaScript, VBScript
OR
Name two server side scripting language and two client side scripting language.
(b) What is the difference between packet and message switching?
Answer:
| Packet switching | Message switching |
| 1. There is a tight upper limit on the block size. A fixed size of packet is specified. | 1. In message switching there was no upper limit. |
| 2. All the packets are stored in main memory in switching office. | 2. In message switching packets are stored on disk. This increases the performance as access time is reduced. |
Question 13.
Meerut school in Meerut is starting up the network between its different wings. There are four buildings named as S, J, A and H. The distance between various buildings is as follows:
| A to S | 200 m |
| A to J | 150 m |
| A to H | 50 m |
| S to J | 250 m |
| StoH | 350 m |
| J to H | 350 m |
Numbers of computers in each Buildings
| S | 130 |
| J | 80 |
| A | 160 |
| H | 50 |
(a) What type of topology is best suited for above network?
Answer:
Star topology
(b) Suggest the most suitable place (i.e. building) to house the server of this school.
Answer:
Building A
(c) The school is planning to link its head office situated in New Delhi with the offices in hilly areas. Suggest a way to connect it economically.
Answer:
Radio waves would be an economic way to connect it.
(d) The company wants internet accessibility in all the blocks. What is the suitable and cost-effective technology for that?
Answer:
BroadbandÂ
Converter 350 Degrees F To C.