Nootan Kumar Mittal ISC Class 12th Chapter 4th {Capacitors and Dielectric (Part I)}

                           Chapter- 4

          Capacitors and Dielectric.

* Capictors (C)

Some electric device required for very high current  ( 25A-50A) to start them (Static Frection) like Fan,Motor etc.

*Function of capacitors

~ stores electric energy & supply it at once (suddenly).

~ Capacitor is a connector which stores electric charge.

*Unit of capacitor.

Capacitor-capacity to hold electrical energy

C is independence of 'Q'  &  'V'

Q--charge

V--electric potential

* Spherical conductor.

Conceptual question

*Parallel plate capacitor

Conceptual question

*Force between the plate of a charged parallel plate capacitor.

*Combinations of capacitors 

In Series

In parallel

*Dielectric in a capacitor.

A dielectric is an insulating material in which all the electron are tightly bound to the nuclei of the atoms.

Do not allow current but allows development of electric .

•Charges are induced in dielectric

•Induced charge density σi.

* Advantages of dielectric.

1) Provides  stability to plates.

2). Prevent plate from sticking to each other.

3). Increase Capacitance.

*Capacitors with partially filled Dielectric.

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*Effect of introduction that dielectric slab between the capacitor plate.

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