Describe how a capacitor works.

If you think of electrons as tennis balls being passed around by a circle of people, then a capacitor occurs when there is a gap between 2 people which is too large for the ball/electron to be passed on. This effectively causes a blockage so that loads of electrons/balls build up on one side of the gap/capacitor. Because elections are negative and on the other side of the gap there are also negative electrons, knowing that the same charged particulate repel, we can work out that the electrons are going to repelled from the other side of the gap, hence leaving more protons than electrons there and causing a positively charged side. These sides are called plates. A capacitor therefore consists of a gap in an electric circuit with one positively charged and one negatively charger plate. 

CW

Related Physics A Level answers

All answers ▸

The Heisenberg Uncertainty principle states that ΔxΔp > h/4π. What is represented by the terms Δx, and Δp? What can we say about p if the precise value of x is known? What does this mean for experimental results.


What is the maximum frequency photon of one of the photons produced when a electron and positron annihilate each other?


How does an object in circular motion experience acceleration when it is going at a constant speed?


2 identical trolleys of mass M(one is loaded with 2 blocks of mass m) are on a ramp inclined at 35° and are connected by a wire that passes around a pulley at the top of the ramp. They are released and accelerate accordingly. Show that a=(mgsin35°)/(M+m).