# basic electric theory (parallel power circuits)

Discussion in 'Homework Help' started by xbox112005, Oct 30, 2011.

1. ### xbox112005 Thread Starter New Member

Oct 30, 2011
9
0
Need help with this question. Two resistors are connected in series.One resistor has a resistance of 1000 ohms,and the other resistor value is not known.The circuit is connected to a 50 v power supply,and there is a current of 25ma flowing in the circuit. If a 1500 ohm resistor is connected in parallel with the unknown resistor,how much current will flow in this circuit?

Last edited by a moderator: Oct 31, 2011
2. ### praondevou AAC Fanatic!

Jul 9, 2011
2,936
489
50V and 25mA gives you the total resistance. Then calculate the unknown resistor.
You will have 1000 Ohms in series with the value just obtained and 1500 Ohms in parallel. Calculate the new total resistance and then the current.

3. ### Nathan Hale Active Member

Oct 28, 2011
125
2
I am getting the answer as 31.25mA. What am i doing wrong?

4. ### praondevou AAC Fanatic!

Jul 9, 2011
2,936
489
Nothing. Why do you think the answer is not 31.5mA?

5. ### xbox112005 Thread Starter New Member

Oct 30, 2011
9
0
thanks but how did you get 42

6. ### Georacer Moderator

Nov 25, 2009
5,151
1,266
This is his profile signature you are commenting upon, not his answer to your original post, a reference to Hitchhiker's guide to the galaxy.

7. ### praondevou AAC Fanatic!

Jul 9, 2011
2,936
489
LOL, that was really funny..............