IT Trainer Questions

The reciprocal of a negative number is always a negative number. So that the number and its reciprocal multiply to 1. 

All real numbers except 0 have reciprocals.

A computer programming language is nothing but a language which is understand by the computer.

Examples of programming languages are Basic, C, Java, Python, ...

The maximum number of characters allowed is 1024 characters.

Kangaroo.

Inheritance is the ability to create new classes based on existing classes. It is useful to reuse existing code.

One of the most common errors that you might face in join statements is 

Server: Msg 4104, Level 16, State 1, Line 1
The multi-part identifier could not be bound.

A multipart identifier is any description of a field or table that contains multiple parts - for instance MyTable.SomeRow - if it can't be bound that means there's something wrong with it - either you've got a simple typo, or a confusion between table and column. It can also be caused by using reserved words in your table or field names and not surrounding them with [].

The main reason for this error is that the source table cannot be found, for example if you have statement such as Table1.OrderDate, and then if you get error above, this means that Table1 cannot be found in the query. Sometimes you can see that source table exists in the query, but T-SQL cannot understand it, especially when you write join statements.

Footsteps. 

Yes, as you walk forward, you will leave the footstep behind you.

Resistivity :

Resistivity is a measure of the resistance to the flow of electrons. 

Conductivity :

Conductivity is just the inverse of resistivity, σ = 1/ρ, where σ is conductivity and ρ is resistivity.

Example:

Think of a pipe and water, the bigger the pipe, the easier water can flow and thus the lower the resistance.