a. Explain what is meant by the time constant of a circuit containing capacitance and resistance.
b. A circuit contains capacitors of capacitance 500 μF and 2000 μF in series with each other and in series with a resistance of 2.5 kΩ.
i. Calculate the effective capacitance of the capacitors in series.
ii. Calculate the charge on the capacitor plates when there is a potential difference of 50 V across the plates.
iii. Calculate the time taken for the charge on the plates to fall to 5% of the charge when there was a p.d. of 50 V across the plates.