Capacitors - Technical MCQs

Q1:

What is the dielectric constant for ceramic?

A between 6 and 8000

B 5.0

C between 5 and 1000

D 3000

ANS:A - between 6 and 8000

The dielectric constant or relative permittivity of a material under given conditions reflects the extent to which it concentrates electrostatic lines of flux. In technical terms, it is the ratio of the amount of electrical energy stored in a material by an applied voltage, relative to that stored in a vacuum. Likewise, it is also the ratio of the capacitance of a capacitor using that material as a dielectric, compared to a similar capacitor that has a vacuum as its dielectric. eg: Air 1 vacuum 1 Paper 4 Rubber 7 Teflon 2.1 Polystyrene 2.5 Bottom line: if you make a capacitor with air as the insulator, and it measures 100 pF, and then change to paper as the dielectric without changing any dimensions, the capacitor is now 400 pF.