hidayah, have you tried just looking these up in your textbook?
Why not dispense with formalities and list the QUESTION numbers, too. =D
1) Why is Ohm's Law not an effective method for solving some electric circuits?
2) Why does the loop rule arise as a consequence of conservation of energy?
3) What is the relationship between the number of branch points and the number of independent current in a circuits?
These are questions that test your understanding of Ohm's law. It sounds like you're having trouble with them because you haven't read the material.
When the one pipe splits into two at a junction some of the water will flow down one pipe and some down the other. How much water flows down each one can be related to say the width of the pipes. Of course the width of the pipes are analogous to the resistance of the wire.
Now the sum of the currents going into each pipe or wire is equal that which has come from the main pipe. This in lay-mans terms is Kirchoffs law.