## Kirchoff’s First Law

Ace to convention current flowing towards the point is taken positively and flowing away is taken negatively.

I_{1} + I_{2 }+ (-I_{3}) + (-I_{4}) = 0

I_{1} + I_{2} = I_{3} + I_{4}

or

ΣI = 0

This equation verifies the law of Conservation of Charge.

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- Applications of Electrostatics
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## Kirchoff’s Second Law (Voltage Rule)

Kirchoff’s Second Rule is the verification of the Conservation of Energy.

### Practically Applicable Solution of Circuit

- Draw the circuit.
- The loops should be chosen so that each resistance is included at least once in each loop.
- Assume the direction of the current is either clockwise or anti-clockwise. All the current loops should be in the same order.
- Write the loop equation:
- The voltage across each resistor is negative.
- Its the direction of flow of current due to the battery (conventional current) and the direction of loop current is parallel then the EMF (electromotive force) of the battery is taken to be positive otherwise negative.

- Finally, solve the equations for each loop simultaneously for unknown quantities.

#### Example

E1 – E2 – IR1 – IR2 =0

or

ΣV=0