• Generally, in a transistor some amount of voltage is required for turning it on.
• This voltage is the cut in voltage. Up to this voltage it exists a nonlinearity in its characteristics. Beyond this cut in voltage the characteristics of transistor is linear.
• This nonlinear region lays between 0-4mA, beyond 4ma it linear. That’s why 4-20 mA range is used.

• 4-20mA has an inherent ‘live zero’. Zero engineering unit is 4mA not 0.0mA indicates an open circuit, fault in the line which is not valid.
• 4-20 mA has little, if any, signal loss in its circuit; current regulation compensates for minor resistances in terminal boxes, whereas voltage drop across resistances for voltage signals creates an error.
• S 4-20 mA signal is less susceptible to noise pickup than a voltage circuit. So it is free from interference from other signals.
• 4-20 mA works at a relatively long distance(>1 Km ) boosting the power supply voltage will drive the signal further.

• f_v is the frequency of vortex shedding.
• D is the diameter of the pipe.
• w is the width of bluff body over diameter of pipe.
• K is the a constant for all fluids given design of meter. A k factor is introduced to compensate for the non-uniform profile of pipe flow.
• S is the Strouhal number, determined experimentally.

• K-factor is a dividing factor.
• The term is usually encountered when dealing with pulse signals although analog K-factors are sometimes used.

• VB.NET offers code execution that runs under the Common Language Runtime (CLR), resulting in robust, stable and secure applications. Both features of the .NET framework are eagerly obtainable in VB.NET.
• VB.NET is object oriented. This is a major addition that VB6 and other earlier releases didn’t have.
• The .NET framework comes with ADO.NET, which follows the disconnected paradigm, i.e. once the required records are fetched the connection no longer exists.
• It also retrieves the records that are expected to be accessed in the immediate future.
• This enhances Scalability of the application to a great extent.
• VB.NET uses XML to transfer data between the various layers in the DNA Architecture i.e. data are passed as simple text strings.
• Error handling has changed in VB.NET. A new Try-Catch-Finally block has been introduced to handle errors and exceptions as a unit, allowing appropriate action to be taken at the place the error occurred thus discouraging the use of ON ERROR GOTO statement. This again credits to the maintainability of the code.

• Pig is a platform for managing large data.
• It uses high level programming to analyse the data.
• The programming is done using the language pig latin.
• It is simple and highly specific.
• The pig Metastore stores all info about the tables. And we can execute spark sql queries because spark can interact with pig Metastore

• Sqoop is a simple tool used for transferring large amount of data.
• It is used for transferring data from hadoop to relational database.
• sqoop can import data from Oracle,MYSQL,SQl.
• Sqoop metastore is a tool for using hosts in a shared metadata repository. Multiple users and remote users execute saved jobs in metastore.

• Staging table is used to stage the exported data.
• Sqoop breaks down method into multiple transactions. A failing job may create partial knowledge.
• This could result in job failing because it could cause duplication of data or even collision while insertion.
• Staging tables are simple database tables that contain business details.
• Staging table acts as an auxiliary table that’s used to transferred data.
• Sqoop breaks down export method into multiple transactions, it’s possible that a failing export job may lead to partial data being committed to the database

• Sqoop is a simple tool that is used for moving data.
• It is generally used move data from non hadoop data stores.
• These non hadoop data stores are the relational databases and data warehouses .
• Sqoop allows the users to specify the target (i.e) the place where the data is to be moved inside of hadoop from relational databases like Oracle,Teredata.
• Data ingestion is important in any big data project because the volume of data is generally in petabytes or exabytes.
• Hadoop Sqoop and Hadoop Flume are the two tools in Hadoop which is used to gather data from different sources and load them into HDFS.

• Sqoop metastore is an internally implemented database that can hold the definition of a given job.
• It includes details like which database,which table,which approach,what query to extract from,what target to write to and so on.
• Consider an array of SQL databases that have the same structure, but are partitioned by for performance reasons.
• Thus we have the same sqoop job running against multiple database instances at the same time, all unified at a single table in Hadoop.
• In order to get parallelization, we generate a job that manages the Sqoop sub-workflows. This results in 500 distinct sqoop jobs.
• Metastore is used to handle these complexities.

• Apache Sqoop is efficiently transferring data between Relational databases and Apache Hadoop.
• It is used to import data from relational databases such as MySQL, Oracle to Hadoop HDFS, and export from Hadoop file system to relational databases.
• It improves the efficiency of data analysis by combining structured data and unstructured data.
• Sqoop stands for SQL for Hadoop.SQL + HADOOP =SQOOP

• To print pyramid triangle in C++, we have use two for loop, the outer for loop and the inner for loop.
• The outer for loop is responsible for rows and the inner for loop is responsible for column.
• C++ programs to print different types of patterns using stars(*), numbers, and characters or alphabets.
• This C++ program prints the full pyramid using stars(*).

Sample Code in C++

#include <iostream>
using namespace std;
   int main()
{
    int j, rows;
       cout <<"Enter number of rows: ";
    cin >> rows;
       for(int i = 1, k = 0; i <= rows; ++i, k = 0)
    {
        for(j = 1; j <= rows-i; ++j)
        {
            cout <<"  ";
        }
        while(k != 2*i-1)
        {
            cout << "* ";
            ++k;
        }
        cout << endl;
    }    
    return 0;
}

Output

Enter number of rows : 7   
            * 
          * * * 
        * * * * * 
      * * * * * * * 
    * * * * * * * * * 
  * * * * * * * * * * * 
* * * * * * * * * * * * * 

• A dangling pointer is pointing to a memory location that has been deleted (or freed). The dangling pointer act as a different ways there are,
  • De-allocation of memory
  • Function Call
  • Variable goes out of scope

To find easy to way of Divisibility by 11,

• The multiples of 11: 22, 33, 44, 55, etc. But we did’t easy to find the number 2728, 54695 is divisible by 11.
• Here an easy way to test for divisibility by 11. Take the alternating sum of the digits in the number, read from left to right. If that is divisible by 11, so is the original number.
• So, for example, 2728 has alternating sum of digits 2-7+2-8 = -11. Since -11 is divisible by 11, so is 2728.
• Similarly, for 54695, the alternating sum of digits is 5-4+6-9+5 = 3. This is not divisible by 11, so neither is 54695.

n = 122164154695
Queries: l = 0 r = 3, l = 1 r = 2, l = 5 r = 9, l = 0 r = 11

True
True
False
True

#include <iostream> 
using namespace std; 
  
const int MAX = 1000005; 
  
// To store sums of even and odd digits 
struct OddEvenSums 
{ 
    int e_sum; // Sum of even placed digits 
  
    int o_sum; // Sum of odd placed digits 
}; 
  
OddEvenSums sum[MAX]; // Auxiliary array 
  
// Utility function to evaluate a character's 
// integer value 
int toInt(char x) 
{ 
    return int(x) - 48; 
} 
  
// This function receives the string representation 
// of the number and precomputes the sum array 
void preCompute(string x) 
{  
    sum[0].e_sum = sum[0].o_sum = 0; // Initialize everb 
  
    // Add the respective digits depending on whether 
    // they're even indexed or odd indexed 
    for (int i=0; i<x.length(); i++) 
    { 
        if (i%2==0) 
        { 
            sum[i+1].e_sum = sum[i].e_sum+toInt(x[i]); 
            sum[i+1].o_sum = sum[i].o_sum; 
        } 
        else
        { 
            sum[i+1].o_sum = sum[i].o_sum+toInt(x[i]); 
            sum[i+1].e_sum = sum[i].e_sum; 
        } 
    } 
} 
  
// This function receives l and r representing 
// the indices and prints the required output 
bool query(int l,int r) 
{ 
    int diff = (sum[r+1].e_sum - sum[r+1].o_sum) - (sum[l].e_sum - sum[l].o_sum); 
  
    return (diff%11==0); 
} 
  
//driver function to check the program 
int main() 
{ 
    string s = "122164154695"; 
  
    preCompute(s); 
  
    cout << query(0, 3) << endl; 
    cout << query(1, 2) << endl; 
    cout << query(5, 9) << endl; 
    cout << query(0, 11) << endl; 
  
    return 0; 
} 

1 
1
0
1

• Sort an array elements means arrange elements of array in ascending order and descending order.

• Find number of digits in the largest number. Let us assume number of digits be n.
• Create extended version of all numbers. In extended version, we have n+1 digit formed by concatenating the number of with itself and truncating extra digits.
• Sorting the value from original numbers according to their extended values.
• Concatenating to the sorted numbers produce the required result.

• Polymorphism means having many forms that in a single entity can takes more than one form.

• • Subtype polymorphism is also known as runtime polymorphism
  • Parametric polymorphism is also known as compile-time polymorphism
  • Ad-hoc polymorphism is also known as overloading
  • Coercion is also known as (implicit or explicit) casting

• In C++, A pure virtual function or abstract function is a virtual function for which we don’t have implementation, we only declare it. A pure virtual function is declared by assigning 0 in declaration.

• Abstract Class is a class which contains atleast one Pure Virtual function.
• An abstract class is a class that is designed to be specifically used as a base class.
• It is used to provide an Interface for its sub classes.
• Classes inheriting an Abstract Class must provide definition to the pure virtual function, otherwise they will also become abstract class.
• You declare a pure virtual function by using a pure specifier (= 0) in the declaration of a virtual member function in the class declaration.

• Dynamic binding (dynamic dispatch) means that a block of code executed with reference to a procedure call is determined at run time.