Current Electricity

1. Heating effect

1.1. Joules Law of Heating

1.2. Heat produced in a resistor

1.3. i)directly proprtional to the square of current for given resistance

1.4. ii)directly proportional to resistance of given current

1.5. iii)directly proportional to time for which current flows through the resistor

1.6. H=I^2Rt

2. Power

2.1. Rate at which electric energy is dissipated or consumed in an electric circuit

2.2. P=VI or P=I^2r=V^2R

2.3. SI unit is watt-- Power consumed by a device carrying 1A of current at a PD of 1V

3. Series and Parallel

3.1. SERIES

3.2. Rs=R1+R2+R3

3.3. Parallel

3.4. Req=1/R1+1/R2+1/R3

4. Resistance and Resistors

4.1. Factors on which resistance depends:

4.2. Area of cross secion of conductor

4.3. Length of conductor

4.4. Material of conductor

4.5. R=pl/A

5. Fuse

6. Potential Difference

6.1. Work done to mov unit charge from one point to another

6.2. SI unit is volt(V)

6.3. 1V=1Joule/1Coulomb

6.4. Measured by voltmeter

7. Current

7.1. Amount of charge flowing through particular area in unit time

7.2. I=Q/T

7.3. Measured in Ampere(A)

7.4. Mesured by ammeter

8. Circuit

8.1. Closed and continuous path of electric current

9. Ohm's Law

9.1. The potential difference across the ends of a given conductor is directly proportional to the current flowing through it provided the temperature remains constant.

9.2. V=IR