Circuit theory is important for electrical engineering, physical science, networking. Circuit theory is the fundamental of electrical engineering. Every electrical engineering students should have clear concept about circuit. We transfer electrical energy one place to another through circuit. In our houses we use different types of circuit for using fan, bulb, iron, fridge, micro oven etc. Before understanding circuit we have must knowledge about circuit element. Each component in a circuit is known as circuit element. Battery, resistor, wire, capacitor, inductor etc are circuit element. See below some practical circuit element

**How to solve circuit**

If you follow the procedure solving a circuit it will be easy. Follow below steps solving electrical circuits.

**Step 1:** Define the problem.

**Step 2**: Present everything what you know about that circuit.

**Step 3: **Think how many alternative solution can be possible. Pick one which is the easiest and give correct answer.

Mesh analysis is a circuit solving procedure using mesh current. In nodal analysis we apply KCL to find unknown voltages. But here using KVL we will find unknown currents using this method. We will use mesh currents instead of element current. Mesh analysis reduces the equations getting current. Nodal analysis can be applied in each general circuit but mesh analysis cannot be applied in each general circuit. Mesh analysis only be applied if the circuit is planer.

Nodal analysis is the method to determine voltage or current using nodes of the circuit. In nodal analysis we choose node voltage instead of element voltages and hence the equations reduces in this process. We have to consider voltage source is not in this circuit. We have to solve a circuit with n nodes without voltage sources. To solve a circuit using nodal analysis method you must have good knowledge about node branch loop in a circuit. If you have no clear idea read the article then come back here. There are three steps to solve a circuit using nodal analysis

Conversion of voltage source into current source is possible when a voltage source is equal to current source. Figure 1 is a circuit of constant voltage source and figure 2 is a circuit of constant current source. If the two circuits are satisfied electrically the same way under all condition then we can convert voltage source to current source having no doubt.

**Nodal analysis with current source**

Nodal analysis is the method to determine voltage or current using nodes of the circuit. In node analysis we choose node voltage instead of element voltages and hence the equations reduces in this process. We have to consider voltage source is not in this circuit. We have to solve a circuit with n nodes without voltage sources. To solve a circuit using nodal analysis method you must have good knowledge about node branch loop in a circuit. If you have no clear idea read the article then come back here other wise what is nodal analysis it will be difficult for you. There are three steps to solve a circuit using nodal analysis

Interconnection of some elements is an electrical circuit. A circuit is a network. So to differentiate between a circuit and a network, we should understand the path of circuit.

**A branch represents a single element such as voltage source or a current source or a resistor.**

We can say that a branch is two terminals of an element. The circuit figure shows 5 branches in the circuit. There is two sources one 20V voltage source, one 4A current source, three resistors. As the circuit contains five elements so it has five branches. Every element has two terminals also.

Electric circuit has many elements like resistor, capacitor, inductor, battery etc. Circuit analysis is the process by which voltage or current is measured across the element. In a complete circuit there are two types of elements found active elements and passive elements.