# circuit questions

• Jun 5th 2007, 02:27 PM
rcmango
circuit questions
heres the pic of whats going on:
http://img471.imageshack.us/img471/5418/untitledfj3.png

In the circuit B, R eq is the total equivalent resistance seen in circuit A. This means that both the circuit B and A batteries have the same current.

What resistance should be used for R in circuit A so that R eq will be 100 ohms?

also, if the battery voltage is 10 volts in circuit A, and the equivalent resistance is 100 ohms, how much power is dissipated by the total resistance in the circuit? and what power is dissipated in each resistor?

thankyou.
• Jun 6th 2007, 05:15 AM
topsquark
Quote:

Originally Posted by rcmango
heres the pic of whats going on: http://img471.imageshack.us/img471/5418/untitledfj3.png

In the circuit B, R eq is the total equivalent resistance seen in circuit A. This means that both the circuit B and A batteries have the same current.

What resistance should be used for R in circuit A so that R eq will be 100 ohms?

also, if the battery voltage is 10 volts in circuit A, and the equivalent resistance is 100 ohms, how much power is dissipated by the total resistance in the circuit? and what power is dissipated in each resistor?

thankyou.

I can't get to this right now. I'll try to get to it tonight. (I'm having eye surgery today and my vision will be blurry until tonight.)

-Dan
• Jun 6th 2007, 06:33 AM
CaptainBlack
Quote:

Originally Posted by rcmango

The resistance Rp of the 120 Ohm and 60 Ohm resistors in parallel is given by:

1/ Rp= 1/120 + 1/60

so Rp=40 Ohm.

This is in series with a resistor of resistance R, so Req= R + 40 Ohm.

RonL