Posted by **Sandhya** on Saturday, May 23, 2009 at 6:04am.

A 12 V battery is connected to 5 mega ohm resistor and a 6 micro farad capacitor and an open switch. After how many seconds will the voltage across the resistor reach 9 V?

Suppose the battery is replaced by 12 V ac with a frequency of 60 Hz.Calculate the Irms in the circuit

- Physics -
**bobpursley**, Saturday, May 23, 2009 at 7:35am
If the resistor is 9v, the capacitor is 3 volts.

Vc=q/C=12/(5E6*6E-6)*e^-t/rc

3*30/12=e^-t/30

take the ln of each side, solve for t.

check my typing, my eyes are blurry this am.

Now for the ac part, Z=5E6+1/(2PI60)*6E-6 figure that, it is nearly all resistive.

Then I=12/Z

I can check your work on this.

## Answer This Question

## Related Questions

- Physics - Could someone please tell me what equations i am suppose to use to ...
- Physics - Took a leaf out of Eileen's book for the picture corresponding to the ...
- Physics - a)In the series circuits, what do you notice about the voltage across ...
- Physics - Two capacitors of capacitance 10 micro Farad and 12 micro Farad are ...
- Circuits - A 3 ohm, a 5 ohm, and a 4 ohm resistor are connected in series across...
- Physics - A)Two identical resistors are connected in parallel across a 30-V ...
- Physics - A)Two identical resistors are connected in parallel across a 30-V ...
- physics - 4.8mF capacitor in series with 500 ohm resistor is connected, via a ...
- Physics - A 80.0 Hz generator with an rms voltage of 150 V is connected in ...
- Physics - A 10-ohm resistor is attached to a 20-ohm resistor in series. This ...

More Related Questions