Unit 2 Capacitors

Question 1

Explain the variation of current in a circuit as a capacitor charges

Answer 1

The current begins at a maximum value then decreases exponentially to zero over time.
As electrons build up on the negative plate they offer increasing opposition to subsequent electrons arriving.
This happens because V(c) is in opposition to V(s)

Question 2

Explain the variation of voltage in a capacitor as it charges

Answer 2

The voltage in the capacitor begins at zero and increase exponentially to the supply voltage.
Electrons flow from the negative plate to the positive plate via the discharge loop.
As the positive plate becomes less positive the discharge current decreases exponentially to zero at which there is zero charge in the capacitor.

Question 3

Explain the variation of voltage in a circuit as the capacitor charges

Answer 3

The voltage decreases exponentially over time from the supply voltage to zero

Question 4

Explain the variation of the voltage in a circuit as the capacitor discharges

Answer 4

Increases exponentially from zero to supply voltage

Question 5

Explain the variation of