mjkpscsnotes

(a)

Which wireless communication channel is most appropriate in each of the following situation?

(i) Communication in a hilly area.

(ii) Very fast communication between two offices in two different countries.

Ans

(i) Radio waves / Satellite

(ii) Satellite

(b)

With what aim UNICODE was developed?

Ans

UNICODE was developed with the aim to conceive a single standard code which could manage to represent all languages of the world

(c)

Expand the following file extensions:

(i) ODF

(ii) XML

Ans

(i) Open Document Format

(ii) Extensible Markup Language

(d)

Give one example of URL and one example of domain name.

Ans

URL: http://www.cbse.nic.in/welcome.htm

Domain name : www.cbse.nic.in

(e)

What is the use of repeater in a network ? How is it different from Hub?

Ans

Repeater is used to regenerate a signal which gets weakened during its transmission.

Difference between Hub and a repeater:

Repeater is used to amplify a weakened signal while a hub is used to redirect the received information to all the connected nodes in a broadcast mode.

(f)

Give two characteristics of Star Topology. Also, show it using a diagram with interconnection of 5 computers.

Ans

Characteristics of Star topology

· Easier to install

· Fault diagnosis is easier

· Easier to expand

· Failure of hub/switch leads to failure of entire network.

· Requires more cable length as compared to Bus topology

(f)

What is snooping?

Ans.

Gaining unauthorized access to another person’s or organization’s data

(a)

Name method is used to extract value of index while using ListBox in Java.

Ans.

getSelectedIndex()

(b)

What is the difference between the use of isSelected and setSelected methods used with JCheckBox in Java?

Ans

isSelected() : Returns true if the checkbox is selected otherwise it returns false.

setSelected() : Checks or Unchecks the checkbox .

(c)

Name any two commonly used methods of JComboBox control.

Ans

getSelectedItem( )

getSelectedIndex( )

setModel( )

(d)

Name any two attributes used in <img> tag of HTML.

Ans

Any two attribute from the following :

SRC / BORDER / ALIGN / HEIGHT /WIDTH /ALT

(e)

How many times the following loops will execute the statements inside it?

Which one of them is Entry Control and which one is Exit Control?

Loop 1.

int j=8,total=0;

while(j>1)

{

total+=j;

j-=2;

}

Loop 2.

int j=8,total=0;

{

total+=j;

j-=2;

}

while(j>1);

Ans.

Both the loop will execute 4 times

Loop 1 is Entry control loop .

Loop 2 is Exit control loop .

(f)

What will be displayed in JtextField1 and jTextField2 after execution of the following loop?

int Total=0,End=10;

for (int Turn=1;Turn<=End;Turn+=2)

Total++;

jTextField1.setText(Integer.toString(Total));

jTextField2.setText(Integer.toString(Turn));

Ans

jTextField1 = 5 // Statement 1

jTextField2 = 11 may also be accepted for Statement 2

(g)

Differentiate between the <BR> and <HR> tags of HTML with suitable example.

Ans.

<BR> forces a line break on the web page while <HR> displays a horizontal line on the web page .

(a)

Write a command to add a NOT NULL constraint on FEES column of a student table.

Ans

ALTER TABLE STUDENT MODIFY FEES DECIMAL(5,2) NOT NULL;

(b)

Write SQL command to create a SAVEPOINT called A1.

Ans

SAVEPOINT A1;

(c)

Define foreign key with reference to RDBMS

Ans

Foreign key is a column within a table that points to a column or group of columns forming a primary key in another table. It is used to link two tables.

(d)

Table BANK has 2 rows and 3 columns. Table CUSTOMER has 4 rows and 3 columns. What will be the cardinality and degree of the Cartesian product of them?

Ans

Cardinality : 8

Degree : 6

(e)

There is a column HOBBY in a Table CONTACTS. The following two statements are giving different outputs. What may be the possible reason?

SELECT COUNT(*) FROM CONTACTS;

SELECT COUNT(HOBBY) FROM CONTACTS;

Ans

Null values are included in query 1 but not in query 2.

(f)

Name the methods used to convert one type of data to another in the following statements of Java.

int Num=Integer.parseInt(jTextField1.getText()) ;

jTextField2.setText(Intger.toString(Num)) ;

Ans.

Integer.parseInt( ) converts String to Integer

Integer.toString( ) converts Integer to String

(g)

Mr. Tondon is using table EMP with the following columns.

ECODE,DEPT,ENAME,SALARY

He wants to display all information of employees ( from EMP table) in ascending order of ENAME and within it in ascending order of DEPT. He wrote the following command, which did not show the desired output.

SELECT * FROM EMP ORDER BY NAME DESC, DEPT ;

Rewrite the above query to get the desired output.

Ans

SELECT * FROM EMP ORDER BY ENAME, DEPT ;

(a)

What will be the content of jTextArea1 and TextField1 after execution of the following statements?

(i)

jTextArea1.setText(“Go\tGreen\nINDIA”);

Ans

Go Green

INDIA

(ii)

String Message=”All The BEST”;

jTextField1.setText((Message.length()-6)+” “);

Ans

(b)

Rewrite the following program code using a while loop :

int Last=Integer.parseInt(jTextField1.getText());

for (int C = 1; C<=Last; C++)

jTextArea1.setText(Integer.toString(C));

Ans

int Last=Integer.parseInt(jTextField1.getText());

int C=1;

while( C<=Last)

{

jTextArea1.setText(Integer.toString(C));

C++;

}

(c)

Observe the following code carefully and find which statement will never get executed in the code.

int Count=1; //Statement 1

do //Statement 2

{ //Statement 3

if (Count<15) //Statement 4

jTextField1.setText(“Jump”); /Statement 5

else //Statement 6

jTextField1.setText("Stop"); //Statement 7

Count+=4; //Statement 8

} //Statement 9

while(t<=15); //Statement 10

Ans

Statement 7 won’t be executed

(d)

Write Java statement to make jButton1 disabled.

Ans

jButton1.setEnabled(false)

(e)

What will be displayed in jTextField1 after the execution of the following code?

int Sum,One=3, Two=5;

Sum= One + Two++;

jTextField1.setText(Integer.toString(Sum));

jTextField2.setText(Integer.toString(Two));

Ans.

(f)

What will be the contents of Text1 and Text2 after the following code is executed?

String Text2,Text1;

Text1= "Good Morning";

Text2= "India";

Text1=Text2.concat(Text1);

Text11=IndiaGood Morning

Text2=India

(g)

Shekher is a junior programmer at Educom enterprises. He created the following GUI in Netbeans.

Help him to write code for the following:

(i)

To calculate Income Tax to be paid and display in jTextField4 on the click of Command Button “Calculate Income Tax” as per the following condition:

If the Basic is less than 50000 then IncomeTax = Basic*0.2

And if is greater or equal to 50000 then IncomeTax = Basic*0.3

Ans

float b = Float.parseFloat(jTextField1.getText( ));

float tax = 0;

if(b<50000)

tax=b*0.2;

else

tax=b*0.3;

jTextField4.setText(“”+tax);

(ii)

To calculate Salary and display in jTextField5 on the click of Command Button “Calculate_Salary”.

Hint:

Salary= Basic+ DearnessAllowance+HouseRentAllowance)-IncomeTax.

Ans

float b,hra,da,tax;

b=Float.parseFloat(jTextField1.getText());

hra=Float.parseFloat(jTextField2.getText());

da=Float.parseFloat(jTextFiled3.getText());

tax=Float.parseFloat(jTextField4.getText());

float sal=b+hra+da-tax;

jTextField5.setText(“”+sal);

(iii)

To clear all Text Fields on the click of Command button “Clear”.

Ans

jTextField1.setText("");

jTextField2.setText("");

jTextField3.SetText("");

jTextField4.SetText("");

jTextField5.setText("");

(a)

What is the use of UPDATE statement in SQL? How is it different from ALTER statement?

Ans

UPDATE command is used to modify existing data in a table.

ALTER is used to modify the structure of an existing table.

(b)

Mr. Shankar created a table VEHICLE with 3 rows and 4 columns. He added 1 more rows to it and deleted one column. What is the Cardinality and Degree of the Table VEHICLE?

Cardinality : 4

Degree : 3

(c)

Consider the following table named “GYM” with details about fitness items being sold in the store. Write command of SQL for (i) to (iv) and output for (v) to (vii).

Table: GYM

ICODE	INAME	PRICE	BRANDNAME
G101	Power Fit Exerciser	20000	Power Gymea
G102	Aquafit Hand Grip	1800	Reliable
G103	Cycle Bike	14000	Ecobike
G104	Protoner Extreme Gym	30000	Coscore
G105	Message Belt	5000	MessagExpert
G106	Cross Trainer	13000	GTCFitness

(i)

To display names of the items whose name starts with ‘A’.

Ans

SELECT INAME FROM GYM WHERE ITEM LIKE 'A%';

(ii)

To display ICODEs and INAMEs of all items, whose Brandname is Reliable or Coscore.

Ans

SELECT ICODE,INAME FROM GYM

WHERE BRANDNAME=”RELIABLE” OR BRANDNAME= ”COSCORE”;

SELECT ICODE,INAME FROM GYM

WHERE BRANDNAME IN(”RELIABLE”,”COSCORE”);

(iii)

To change the Brandname to “Fit Trend India” of the item, whose ICODE as “G101”.

Ans

UPDATE GYM SET BRANDNAME=”FIT TREND INDIA” WHERE ICODE=”G101”;

(iv)

Add a new row for a new item in GYM with the details :”G107”, “Vibro exerciser”, 21000,”GTCFitness”

Ans

INSERT INTO GYM VALUES (”G107”, “VIBRO EXERCISER”, 21000,”GTCFITNESS”);

(v)

SELECT COUNT(DISTINCT(BRANDNAME)) FROM GYM;

Ans

COUNT(DISTINCT(BRANDNAME))

(vi)

SELECT MAX (PRICE) FROM GYM;

Ans

Max(PRICE)

30000

(vii)

SELECT INAME FROM GYM WHERE INAME LIKE “%T”;

Ans

INAME

Message Belt

(a)

Write MySql command to create the Table Vehicle with given constraint.

Table CHALLAN

COLUMN_NAME	DATATYPE(SIZE)	Constraint
Challan_No	Decimal(10)	Primary Key
Ch_date	Date
RegNo	Char (10)
Offence	Decimal (3)

Ans

CREATE TABLE CHALLAN

(

Challan_No DECIMAL(10) PRIMARY KEY,

Ch_date DATE,

RegNo CHAR(10),

Offence DECIMAL(3)

);

(b)

In a Database Karnataka_Sangam there are two tables with the instances given below:

Table : STUDENTS

ADMNO	NAME	CLASS	SEC	RN	ADDRESS	PHONE
1211	Meena	12	D	4	A-26	2345678
1212	Vani	10	D	1	B-25	5456789
1213	Meena	12	A	1
1214	Karish	10	B	3	AB-234	4567890
1215	Suraj	11	C	2	ZW 12	4345677

Table : SPORTS

ADMNO	GAME	COACHNAME	GRADE
1215	Cricket	Mr. Rai	A
1213	Vollyball	Ms. Chadha	B
1211	Vollyball	Mr. Govardhan	A
1212	Basket Ball	Mr. Tiwani	B

Write SQL queries for the following

(i)

To count how many addresses are not having NULL values in the address column of students table.

Ans

SELECT COUNT(ADDRESS) FROM STUDENTS;

SELECT COUNT(*) FROM STUDENTS WHERE ADDRESS IS NOT NULL;

(ii)

To display Name, Class from STUDENT table and the corresponding Grade from SPORTS table.

Ans

SELECT NAME, CLASS, GRADE FROM STUDENT, SPORTS

WHERE STUDENT.ADMNO =SPORTS.ADMNO;

(iii)

To display Name of the student and their corresponding Coachnames from STUDENTS and SPORTS tables

Ans

SELECT NAME, COACHNAME FROM STUDENT, SPORTS

WHERE STUDENT.ADMNO=SPORTS.ADMNO;

(c)

Answer the questions (i) and (ii) based on the following table:

Table:FACULTY

FNO	FNAME	AGE	DEPARTMENT	GRADE
111	Moksha	40	Biology	A
123	Malini	35	Maths	A
125	Akshit	43	English	B
130	Nishant	27	Maths	B

(i)

Identify Primary key in the table Faculty.

Ans

FNO

(ii)

Write SQL command to change the grade of Nishant to “A”.

Ans

UPDATE FACULTY SET GRADE=”A” WHERE FNAME=”NISHANT”;

(a)

How popularity of e-Commerce has benefitted a common man? Give the domain name of one popular e-Commerce site.

Ans

Benefits of e-Commerce

(i) Helps reach customers effectively and speedily

(ii) Helps customers to order on-line

(iii) Helps in getting feedback from customers

(iv) Helps business transactions

Example:

www.amazon.com

www.ebay.com

any one e-Commerce site

(b)

Give two addresses of most commonly used e-Learning sites.

Ans

www.w3schools.com

www.ncert.nic.in

(c)

Shobhit is creating a form for his company. Help her to choose most appropriate controls from ListBox, ComboBox, TextField, TextArea, RadioButton, Checkbox, Label, and Command Button for the following entries

S.No.	Function
1	To select citizenship from a list of countries
2	To allow to input grade out of ‘A’ to ‘D’
3	To allow selecting one or many food items
4	To allow entering Feedback in the form of a paragraph

Ans

S.No.	Function	Control
1	To select citizenship from a list of countries	Listbox/Combobox
2	To allow to input grade out of ‘A’ to ‘D’	Radio Button/Combo Box
3	To allow selecting one or many food items	ListBox/Check Box
4	To allow entering Feedback in the form of a paragraph	Textarea

mjkpscsnotes

Monday, September 22, 2014

Informatics Practices Past year CBSE paper1

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