Electrical Theory

Equation for Capacitance

Capacitor can be defined as device including two electrically conductive metal plates that are arranged parallel to each other. These two plates are separated by a insulating medium. Due to this arrangement, an electrical charge is established.  Here the charge is flowing from the positively charged plate to the negatively charged plate. It measures the ability of capacitor to store charge. It can be expressed as following equation:
C=Q/V
Where
C=capacitance
Q=charge on each plate
V=Voltage supplied to plates
Here since Q is measured in coulomb and V is measured in volt, the unit of capacitance is Farad.

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Measuring Capacitance

This (CP) could be measured by various methods. First one is to use CP-measuring meters namely DMM (digital multi meter) and LCR meter. Other method to measure CP relies on resistance and time. It includes measurement of time (T) taken to charge a battery of particular voltage. The resistance (R) of capacitor is measured in Ohm. Using the above mentioned values, CP can be calculated by following formula:
C=T/R
CP can also be measured by charging the capacitor with a constant current (I). Here
C=I*T

Capacitance Measurement

CP can be easily measured by using the CP-measuring meters that cover wide range. Other methods to measure CP depend on measurement of time taken to charge a battery of known voltage or on supplying a constant current to the capacitor.

Units for Capacitance

Since CP is measured by dividing charge on each plate of capacitor to the voltage supplied, its unit is farad. Here the formula is C=Q/V.
In case of following formula:
C=T/R;
If the resistance is measured in Ohm, the unit of CP will be farad. But if the resistance is measured in mega-ohm, unit of CP will be microfarads.

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Electronic Theory

Electricity is produced due to movement of electrons through conductor materials. It involves movement of electrons towards proton driven by electromotive force. This force is responsible for pushing the electrons towards the protons. Now the atom that has lost the electron becomes positively charged and it attracts electron from other atoms. Hence there is a chain reaction of gain and loss of electrons between atoms. In a conductor, electrons move towards positively charged plate and this movement is driven by potential difference between the two plates. According to the electronic theory movement of electron occurs from negative end to the positive end of electronic circuit.