Explain capacitance to me please?

Question

HI there - I need someone to explain capacitance to me WITHOUT USING THE EQUATION!!! Or use the equation to make the point at the end of the explanation - but I know the equation, now I need a way to understand it in my head so that it will make sense. Please explain capacitance from this question: =====> Lightning is the transfer of charge across the potential difference between a cloud and the ground. The Earth's surface and the bottom surface of a typical thunder cloud may be thought of as a parallel plate capacitor. Explain why the potential difference between the cloud and the ground DECREASES as the cloud moves closer to the ground.

Answer 1

it's tough without the equations.

This is not an explanation of capacitance, that you appear to be asking, but an explanation of voltage on a cloud and how it changes.

"Explain why the potential difference between the cloud and the ground DECREASES as the cloud moves closer to the ground"

The charge on the cloud is fixed (relatively, see note 3). Since voltage is inversely proportional to capacitance (one equation), moving the cloud closer to the ground increases the capacitance (second equation), and therefore decreases the voltage.

Equation 1: Q = CV or V = Q/C

Equation 2: C = kA/d (parallel plate capacitor)

Note 3: Now you could maintain that the charge is changing and this is not valid, and you would be correct. But then you get into a difficult mathematical area, with two quantities changing at once. This is a simplification.

Answer 2

A capacitor is basically two conductors separated by an insulator.  One type of capacitor used in electronics has two strips of foil separated by a thin layer of plastic, rolled up into a cylinder.  The larger the area of the foil, and the thinner the insulator, the higher the capacitance.  When a voltage is applied to the capacitor, one plate becomes positive and the other negative, and the charges would jump between the plates except that the insulator does not let them.  The voltage will stay on the capacitor for a long time, and can make a spark if the plates are connected together by an external wire.

The cloud can build up a charge when it loses or gains electrons, and the air between the cloud and the ground acts as the insulator of a giant capacitor.  If the charge builds up to a high enough voltage, the air ionizes and becomes a conductor, and the charges are equalized again.  The closer the cloud is to the ground, the lower the potential difference (voltage) has to be for a spark to jump.

Answer 3

voltage is dependent upon a gap to discharge to ground,similar is the fact that if a spark plug gap is too wide it will not discharge to ground.the clouds have a positive energy and the ground has a negative energy and until the clouds are close enough to the ground the electricity cannot"jump" the gap.the energy of the atmosphere between the ground and clouds I'm sure in some way adds to the total charge of the lightening bolt.