## 1. Electric Current

### 1.1. I = Q/t

### 1.2. Unit of I is Ampere (A)

## 2. Potential Difference

### 2.1. V=W/Q

### 2.2. Unit of Potential Difference is Volt

## 3. Ohm's Law

### 3.1. V=IR

### 3.2. R=V/R

### 3.3. Unit Of R is Ohm

## 4. Resistance R = ρ l/a

### 4.1. R depends on - Length of conductor

### 4.2. R depends on - Area of cross section

### 4.3. R depends on - Nature of material

## 5. Resistence of system of resistors

### 5.1. Resistance in series

5.1.1. R= R1 + R2 + R3 + .....

### 5.2. Resistance in parallel

5.2.1. 1/R = 1/R1+1/R2+1/R3 + ..

## 6. Heating Effect of Electric Current

### 6.1. Power input to the circuit

6.1.1. P = VI

### 6.2. Joules law of heating

6.2.1. H = I²Rt

### 6.3. Practical Application of heating effect

6.3.1. :Electric laundry iron

6.3.2. Electric toaster

6.3.3. Electric kettle

6.3.4. Electirc oven

6.3.5. Electric heater

## 7. Electric power

### 7.1. P = VI = I²R = V²/R

### 7.2. Unit of power is Watt (W)

### 7.3. Commercial unit of electrical energy is Kilowatt hour (kWh)

7.3.1. 1kWh = 3.6 x 10⁶ Joule