Factors affecting capacitance, Physics

Assignment Help:

Factors affecting capacitance:

The factors which affect the capacitance of a parallel-plate capacitor are:

  • Overlapping area of the plates (A). The capacitance increases as the area of overlap increases since a larger plate area provides more room to accommodate the increase charge.
  • Distance between the plates (d). The capacitance increases as the distance between the plates decreases, since the electric field then becomes more concentrated.
  • Material between the plates. This introduces a constant called the absolute permittivity (ε). The constant  ε is actually the product of two constants, the permittivity of space ( εo) which has a value of 885 x 10-12 Fm-1 and the relative permittivity (εr), which is basically a multiplication factor (no units) that indicates how many more times the material is able to concentrate the electric flux compared with space. For example, if waxed paper is inserted between the plates instead of air, the ability to concentrate a flux (the permittivity) is multiplied by approximately 3, therefore the relative permittivity ( εr) of waxed paper is approximately 3.

We may summarise this in equation form as:

                  C = εA/d

The units of 'C' are Farads if the units of the other quantities are:

  • Area (a) - square metres (m2).
  • Distance between plates (d) - metres (m).
  • Absolute permittivity (ε) - farads per metre (Fm-1).

In the case of multi-plate capacitors, capacitance is calculated using the formula: C = [(n-1)εA]/d

Where n is the number of plates and A is the area of a single plate.

 


Related Discussions:- Factors affecting capacitance

Determine the characteristics of the filter, 1. We want to measure a sinuso...

1. We want to measure a sinusoidal signal (frequency 100 Hz) expected to be of strength 1 mV RMS in the presence of noise of peak amplitude 3 mV.   (a) If our A/D converter has

Potential difference, Potential difference: When charges move from one ...

Potential difference: When charges move from one point to another, it is not the actual values of potential at those points which are Important, but the potential different (pd

Infra-red detectors and optic lens, Infra-Red (IR) Detectors:   An IR ...

Infra-Red (IR) Detectors:   An IR detector has an impedance of Z= (400+j200) ?  . During design  tests the detector  current  is measured  as  4  µA. What  is  the output v

Magnetic , #questionMnS is a paramagnetic solid. At 300°K, there are 4 × 10...

#questionMnS is a paramagnetic solid. At 300°K, there are 4 × 1022 molecules of MnS per cm3. If the cationic magnetic moment of MnS is 5 MB, use the Curie law in 8-b to compute the

Moment of inertia, Moment of Inertia In this section we get formulae for...

Moment of Inertia In this section we get formulae for determining the moment of inertia or second moment of a mass around an axis for several common physical shapes. The mome

Explain newton’s law of cooling , It is described to this law, if the tempe...

It is described to this law, if the temperature T of the object is not very dissimilar from that of the environment T0, then rate of cooling -dT/dt is proportional to the temperatu

Find the temperature of the gas?, In accrued model of a rotating diatomic m...

In accrued model of a rotating diatomic molecule of (Cl 2 ), the two Cl atoms are 2.00´ 10? -10  m apart and rotate about their center of mass with angular speed w = 2.00 ´10 12 ra

Determine the acceleration, Q. A truck loaded with sand accelerates along ...

Q. A truck loaded with sand accelerates along a highway. If the driving force stays the same on the truck, what happens to the truck's acceleration if its trailer leaks sand at a

Explain about soft iron armatur, A force of 2.5kN is needed to lift a load....

A force of 2.5kN is needed to lift a load. How much work is done if the load is lifted by 500cm? An electromagnet exerts a force of 12N and moves a soft iron armature by a dist

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd