Electricity

1. Resistance

1.1. Ohm's Law

1.1.1. Potential difference is directly proportional to electric current, given temperature is constant.

1.2. V=IR

1.2.1. {Here R is Resistance and I is Amperes}

1.3. Represented by the symbol Ω [Ohms]

1.4. Factors on which Resistance depends

1.4.1. Length [ R∝L ]

1.4.2. Area of Cross section [R∝1/A]

1.4.3. Nature of Material

1.4.4. Temperature of the Conductor

1.5. The inherent property of a conductor to oppose the flow of electric current.

2. Resistivity [ Specific Resistance ]

2.1. Electrical Resistance offered by a conductor of unit length and unit cross sectional Area at a specific temperature.

2.2. SI Unit is Ω m {Ohm - meter}

2.3. Factors on which Resistivity depends

2.3.1. Temperature of the conductor

2.3.2. Nature of the material

2.3.3. Resistivity is constant for a given material

2.4. Metals are used to make Electricity Transmission Lines

2.4.1. Reason : Resistivity is low

2.5. Alloys are used in toasters and ovens etc

2.5.1. Reason : Alloys do not oxidize at even at high temperatures.

2.6. Insulators are used to cover current carrying conductors

2.6.1. Reason : They have very high resistivity

3. How is Resistance and Resistivity Different ?

4. Electric circuit is a closed path for electric current to flow

4.1. Conventional current

4.1.1. Flow of Protons

4.2. Electron Current

4.2.1. Flow of Electrons

4.3. Materials

4.3.1. Conductors

4.3.2. Insulators

4.3.3. Super conductors

4.3.4. Semi conductors

5. Electric charge

5.1. SI Unit : Coulomb [C]

6. Electric Potential

6.1. Measured By Voltmeter

6.1.1. Connected in parallel

6.2. Unit : Volts

6.2.1. Scalar Quantity

6.2.2. V=W/Q

6.2.2.1. Joules/Coloumb

6.3. Work done in bringing a unit positive charge from one point to another.

7. Electric Current

7.1. charges flowing through a conductor at a particular area in a unit time

7.2. SI Unit : Amperes [A]

7.3. Formula : W/V

8. Heating Effect of Electric Current

8.1. Joule's Law of Heating

8.1.1. The heat which is produced due to the flow of electric current within an electric wire.

8.1.2. SI unit is Joule

8.1.3. H=I²RT