Questions

Hub works on layer 1 i.e, physical layer.

The memory which can be retained even the power is off is called as Permanent memory or Persistent memory. Computer's hard drive is an example of permanent memory and computer's cache or RAM are examples of temporary memory.

To create a simple electromagnet, you'll need a source of electricity, a conductor, and metal. Wrap insulated copper wire tightly around an iron screw or nail before connecting the wire to a battery, and watch as your new electromagnet picks up small metal objects.

Scheduling is the activity of the deciding when process will receive the resources they request.

FCS ---> FCSFS stands for First Come First Served. In FCFS the job that has been waiting the longest is served next.

Round Robin Scheduling--->Round Robin scheduling is a scheduling method where each process gets a small quantity of time to run and then it is preempted and the next process gets to run. This is called time-sharing and gives the effect of all the processes running at the same time

Shortest Job First ---> The Shortest job First scheduling algorithm is a nonpreemptive scheduling algorithm that chooses the job that will execute the shortest amount of time.

Priority Scheduling--->Priority scheduling is a scheduling method where at all times the highest priority process is assigned the resource.

Demand is said to be inelastic, when the demand for the good doesn't change much or it is negotiable when the price of the good changed.

The difference between Union and Union all is that Union all will not eliminate duplicate rows, instead it just pulls all rows from all tables fitting your query specifics and combines them into a table. A UNION statement effectively does a SELECT DISTINCT on the results set.