A capacitor of capacitance 
and a resistor of resistance 
are connected as shown in the figure below.
Initially, the capacitor is charged and the switch is open. The switch is closed at time 
. The graphs below show the variations with 
of the charge 
on the capacitor and the potential difference (p.d.) 
across the resistor.
The time constant of the circuit in the figure above is 
. Use the two graphs above to determine:
capacitance , in 
resistance in 
.
.
.
