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Q2. A 100 μF capacitor and an 82 1k Ω resistor are connected in series to a 24 V d.c. power supply.

(a) Calculate EACH of the following.

(i) the instantaneous current when the supply is switched on. (2)

(iii) the capacitor voltage 5 second's after switch-on. (3)

(iii) the charge stored in 'the capacitor 5 seconds after switch on. (2)

b) After 5, seconds of charging the supply is switched off, the 82 k Ω resistor is replaced with 27 k Ω through which the capacitor, discharges.

(i) Calculate the time taken for the capacitor voltage to fall to 4 V. (3)

(iii) Using approximately scaled axes, sketch graphs of capacitor voltage against time for charge and discharge indicating EACH of the following:

• the supply voltage

• the voltage 5, seconds after switch-on

• initial discharge voltage

• the tim1e when the voltage is 4 V. (16)