Calculating Voltage Decay in a Resistor-Capacitor Circuit

[SMUDGY]

If a charged capacitor c=35 micro farads is connected to a resistor R=120 ohms how much time will elapse until the voltage falls to 10^6/D of its original max value?

Ciruit contains a switch, resistor, emf and a capacitor in series.

Relevant equations are Time constant= T=cR and V(Final)=V(initial) e^-t/cr


I think it requires logarithms but i am not sure.

Can you please help me how to answer this.

 

[SMUDGY]

Another question is:

A circuit containing a switch, Vo, a capacitor and a bulb in series.

The capacior is originally uncharged. Describe the behaviour of the bulb from the instant the switch is on until a long time later.

I think there will be a delay for the bulb to emit light and then it will emit light getting slowly brighter as the capacitor is getting charged up.

Is this right?