1. How is Electricity generated in power plants?
Using coal
Using wind
Using hydro power
Solar

2. AC vs DC
DC, or direct current means the electrical current is flowing in only one direction in a circuit.
Batteries are a good source of direct current (DC).
AC, or alternating current means the electrical current is alternating directions in a repetitive pattern.
AC is created by generators in power plants, and other sources.

3. DC and AC waveform Time Time
Can be triangular wave, square wave or any symmetrical waveform

4. Switches to convert DC to AC??
A diode allows current to flow in one direction only.
A capacitor stores energy and dissipates