3i Infotech Papers: Sample Questions 1071 - 1073 of 1245

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Question number: 1071

» Languages » Assembly Language

Short Answer Question▾

Write in Short

Super Key is

Explanation

  • A super key is a set or one of more columns to uniquely identify rows in a table.

  • Students are confused between super key and candidate key.

  • Candidate key is a column, or set of columns, that uniquely identify any database record without referring to any other data. A table may have one or more candidate keys, but one candidate key is unique- the primary key. .

  • Adding any other column or attribute added to a Primary Key makes it a super key.

  • Thus super key is primary keyattribute.

Question number: 1072

» Basic CS » Algorithms

Essay Question▾

Describe in Detail

What are tri-state device and why they are essential in a bus oriented system?

Explanation

A tri-state device has three terminals.

Image of the three terminals

Image of the Three Terminals

Image of the three terminals

  • When enables line is active output line follows input line, otherwise output line is free.

  • It helps bus oriented system.

    • Consider two buffers working on inverted logic.

    • Two buffers are receiving different inputs and the output of two buffers is connected to same bus.

    • Enabling and disabling enable line of two buffers selectively allows one of the inputs on the bus.

Question number: 1073

» Languages » C & C Plus Plus

Essay Question▾

Describe in Detail

What do you mean by multiple inheritance and multilevel inheritance? Differentiate between them.

Explanation

Multiple Inheritances:

Define Multiple inheritance.

Define Multiple Inheritance.

Define Multiple inheritance.

  • A class can inherit from more than one classes.

  • More than one parent classes

  • This is not parent in java.

  • Example: two class A and B as the parent classes of class C, then we define C as follows.

class C: public A, public B

{

//code

};

Multilevel Inheritance:

Understanding of multilevel inheritance.

Understanding of Multilevel Inheritance.

Understanding of multilevel inheritance.

  • Class having more than level of parent classes produces multilevel inheritance.

  • The level of inheritance depends on the relation- similar to relation between grandfather, father and child.

  • Example:

class A

{

…………

};

class B: public A

{

……………

};

Class c: public B

{

………………

};