Questions

Alternating Current (AC) is the current in which flow of current is altered periodically whereas in DC current i.e, direct current the flow of current is only in one direction.

Some of the sources of AC current are :

1. Hydro-electric generators

2. Thermal power generators

3. Nuclear  power generators...

A program is a group of related projects managed in a coordinated way to obtain benefits and  control  not available from managing them individually. Programs may include elements of related work outside of the scope of the discrete projects in the program.

For example:

A New car model program can be broken up into projects  for the design and upgrades of each major component (transmission, engine, interior, exterior) while the ongoing manufacturing occurs on the assembly line

The outer most electrons that are free to move are called valency electrons that are responsible for the conductivity in the metal atoms.