Ladder Diagram PLC Programming and Solar Power

Hello all,
This is my entry to the contest, "Ladder Diagram PLC Programming and Solar Power."

A. What is meant by ladder diagram PLC programming? Draw a ladder diagram and explain.
Ladder programming is a graphical programming language used in industrial automation systems. It can basically be used to program the programming logic controllers (PLCs) in various industries.

B. Write the work by drawing the symbols of the input and output elements of the ladder diagram.
Here, I have mentioned the working principle of OR gate using ladder programming.

C. Draw the ladder diagram with three input ladder logic gates (AND, OR) and explain with practicals.
[With symbols and truth tables]
Here I have given the ladder diagram for three inputs OR gate.

Below is the truth table for the above ladder diagram.

D. Convert the electrical wiring in the figure below into a ladder diagram.

E. Solar power is generated in your home with three 12-volt 100 AH batteries. An additional 12-volt 100 AH battery needs to be connected as your home's electrical load increases. Explain the series and parallel connection of four batteries with diagrams.

The above image shows a series connection of batteries, which gives a summation of the individual voltages of each battery. The above image shows a parallel connection of batteries, which gives a summation of the individual currents of each battery.