# Electronic Machines and Control: Revision

$$V = IR$$

$$Q = IT$$

$$W = I^2 RT$$

$$P = \frac{I^2 RT}{T} = I^2 R$$

## Kirchoff's Current Law

Conservation of charge: sum of current entering a point is zero.

$$\sum_{k=1}^{n} I_k = 0$$

## Kichoff's Voltage Law

Sum of voltage in a closed loop is zero; where the direction of the loop follows the direction of voltage.

## Voltage Divider Rule/Potential Divider

$$V_{out} = \frac{Z_2}{Z_1 + Z_2} V_{in}$$

## Current Divider Rule

$$I_{R1} = \frac{R_2 + \cdots + R_n}{R_1 + R_2 + \cdots + R_n}I_{sum of current in branches past R_1}$$