CBSE Guess > Papers > Important Questions > Class XII > 2011 > Computer Science > Computer Science By Mr. Kapil Bhatia
CBSE CLASS XII
Basic Theory (Part 2)
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- What are Repeaters?
Ans. A repeater amplifies the input signal to an appropriate level and work at physical level of the OSI model. Some time the signals on the internet become weak before reaching the destination node. Repeater is used to regenerate the incoming packet and amplify it and then transmit it to another segment of the network.
- What is Mosaic used for?
Ans. Mosaic is a UNIX based program used to browse the internet.
- What is a Pointer?
Ans. A Pointer is a special data type variable that stores the address of the location in the memory, where the data has been stored.
- What is a Queue?
Ans. A queue is a FIFO type non-primitive linear data structure with two open ends, one called the Front where data is accessed and another called the Rear, from where data is added.
- What do you understand by stream?
Ans. A queue is a FIFO type non-primitive linear data structure with two open ends, one called the Front where data
- Differentiate between CREATE TALE and CREATE VIEW commands in SQL.
Ans. CREATE TABLE is used to create a relational table. When the table is created its column are named, data types and size are supplied for each column. Each table must have one column.
CREATE VIEW is a virtual table with no data, but can be operated line any other table. It is like a window through which you can view the data of another table.
- What is Router?
Ans. Router is a device that works like a bridge but can handle different protocols.
- What is the use of MODEM?
Ans. A modem is a computer peripheral that allows you to connect and communicate other computer via telephone line. Modem converts the digital signal into analog and analog signal to digital.
- Define the inheritance.
Ans. Inheritance is the capability of one class to inherit the properties from another class. This support reusability of code.
- Define infix notation, prefix notation and postfix notation.
Ans. Infix notation:- in infix notation the operator of a binary operation is placed between two operands. For Example A + B
Prefix notation:- In prefix notation the operator of a binary operation is placed before both the operands. For example + A B
Postfix Notation;- In postfix notation the operator of a binary operation is placed after both the operands. For Example AB+
Submitted By Mr. Kapil Bhatia
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