CBSE Class 12 Informatics Practices Sample Paper 2012 Set D

SECTION -A

1. Answer the following questions :

(a) Define Data Warehousing and explain its usage. 

(b) What do you understand by the term SDLC ? Name its essential components. 

(c) Explain the term Front End Tool and Back End Tool in the context of software development process. 

(d) What is the Entity Relationship Model ? Explain the concept of ER Model using the case study of a School that has three entities : Student, Teacher   and Subject. Assume that each student can study more than one subject while each teacher can teach only one subject. 

2. Answer the following questions :

(a) What are conditional or decision control statements ? Name the two conditional statements used in Visual Basic. 

(b) Differentiate between public and private variables and discuss their scope of visibility. 

(c) Explain the terms ODBC and OLE-DB. 

(d) Differentiate between SDI Form and MDI Form in Visual Basic. In the Similar context, explain the concept of parent and child forms

3. Answer the following questions :

(a) Differentiate between DML and DCL giving suitable example in each case. 

(b) What is NULL value ? What is the result of an arithmatic operation containing NULL value ? 

(c) What is the use of a Sub-Query ? Which query gets executed first, the parent query or the sub query ? 

(d) Which PL/SQL command is used to display an output on the screen ? Also name the command used to enable the server output option before using the above command.

(e) Differentiate between Row-level and Statement-level triggers in PL/SQL.

Please refer to attached file for CBSE Class 12 Informatics Practices Sample Paper 2012 Set D