Paper 3: Require practical 9 - Charging and discharging capacitors flashcards

Question 1

What must always be checked when using an electrolytic capacitor in a circuit?

Answer 1

• The electrolytic capacitor is a polarised component and so must be connected with the correct polarity in the circuit
• If connected incorrectly, it can overheat and become a safety hazard

Question 2

What graph can be plotted to confirm the exponential decay of a capacitor’s potential difference as it discharges?

Answer 2

A graph of ln(V/V0) against t can be plotted - should form a straight line

Question 3

When plotting a discharge graph of ln(V/V0) against t, how can the capacitor’s time constant be obtained?

Answer 3

The graph will have the equation of ln(V)=ln(V0) -t/RC
The time constant is -1/gradient

Question 4

What is the benefit of doing a trial discharge before carrying out this experiment in full?

Answer 4

Allows you to choose a suitable time interval to take recordings at, dependingon how quickly the capacitor discharges