How to find the voltage and current of this circuit

In summary: By the way, if you're going to criticize, please use proper capitalization and punctuation when you do so. Thanks.In summary, the conversation discussed how to find V, I2, and I3 in a circuit using the formula V=IR. The voltage was found to be 152V, but the current could not be determined. A detailed solution was requested, but the policy of the forum is to provide hints and guidance rather than doing the work for the poster. Eventually, a solution was provided and the poster was able to use it to solve similar problems.
  • #1
silvercats
60
0
how to find V,I2 and I3 of this.

http://oi52.tinypic.com/10pypw9.jpg

simplified and By putting V=IR
19*8=152
Found the voltage.
But can't find I.

detailed solution expected.
thank you
 
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  • #2
Please note: I am moving this question to "Introductory Physics", since it is more appropriate there.

silvercats said:
how to find V,I2 and I3 of this.

http://oi52.tinypic.com/10pypw9.jpg

simplified and By putting V=IR
19*8=152
Found the voltage.
But can't find I.
What is the voltage across the 4-ohm resistor, and therefore across the 20-ohm resistor? That should help you with finding I2.

detailed solution expected.
Sorry, that is not how this forum works. Please review our forum rules on getting homework help by scrolling down to the section titled Homework Help at our rules page here:
https://www.physicsforums.com/showthread.php?t=414380
 
  • #3
What is the voltage across the 4-ohm resistor, and therefore across the 20-ohm resistor? That should help you with finding I2.

4ohm resistor:V=IR
V=8*4
V=32 <<<i think it ok?
/
How am i supposed to find the voltage of 20ohm one without knowing its current(I)?:eek:
 
  • #4
You have the battery voltage and the voltage drop on the 4 Ohm resistor. What does that suggest?
 
  • #5
Given are the total current (8A) and values of the resistors R1(4ohms),R2(20ohms), and R3(60ohms).
V=IR where R is the total resistance and R= R2R3/R2+R3 or (20*60)/20+60= 15ohms

The total voltage is 8A*(15+4)ohms = 152V

Now the voltage across R1 is IR1: 8A*4Ohms = 32V so the "balance" is 120V across R2//R3.

So 120V/15ohms=6A and 120V/60ohms=2A.

Does this help?
 
  • #6
It not only helps, it answers the question without the poster having done any work for himself. Not a good learning experience :frown:

The policy here is to provide encouragement, hints, theoretical background, and so forth, so that (hopefully) the querents can work through to, or be guided to, solutions themselves. Just doing the homework for others is frowned upon (it can in fact lead to account cancellation).

Other than that, welcome to Physics Forums, Drohm :smile:
 
  • #7
Thanks 'Redbelly98' for answering...!
 
  • #8
It not only helps, it answers the question without the poster having done any work for himself. Not a good learning experience
Yup I didn't do any work.But using this his example ,I did many other questions like this!

Actually gneill,your hint didn't do a good job.Those hints confuse at all.No offense .Thanks for helping
 
  • #9
Does this help?
HELL YEAH! thanks.i was able to do more questions like this using your answer.Keep up the good work.Thanks...
 
  • #10
silvercats said:
detailed solution expected.

lol. why would anyone respond to such an absurd demand?
 
  • #11
silvercats said:
It not only helps, it answers the question without the poster having done any work for himself. Not a good learning experience
Yup I didn't do any work.But using this his example ,I did many other questions like this!

Actually gneill,your hint didn't do a good job.Those hints confuse at all.No offense .Thanks for helping

No offense taken. Let us hope that you have similar templates available for exams.
 
  • #12
why would anyone respond to such an absurd demand?
lol isn't this a violation of forum rules?Talking off topic and rant
 
  • #13
No offense taken. Let us hope that you have similar templates available for exams.
yeah let's hope so :wink: :P
 
  • #14
newyorkcity said:
lol. why would anyone respond to such an absurd demand?

silvercats said:
lol isn't this a violation of forum rules?Talking off topic and rant
At this forum, it's a bigger violation to (A) say you want a detailed solution to a homework problem or (B) provide a detailed homework solution. Did you read the homework help section of our rules yet?
 

1. How do I determine the voltage and current in a circuit?

The voltage and current in a circuit can be determined using Ohm's Law, which states that voltage (V) is equal to current (I) multiplied by resistance (R). So, to find the voltage, you would need to have the values of current and resistance. You can measure the current using an ammeter and the resistance using a multimeter. Once you have these values, simply multiply them to find the voltage (V = I * R).

2. Can I use a voltmeter to find the voltage and current in a circuit?

Yes, you can use a voltmeter to find the voltage in a circuit. However, a voltmeter measures the potential difference between two points in a circuit, so you would need to measure the voltage at different points and then use Ohm's Law to find the current. It is more accurate to use an ammeter to directly measure the current in the circuit.

3. What is the difference between AC and DC voltage and current?

AC (alternating current) voltage and current vary in direction and magnitude over time, while DC (direct current) voltage and current remain constant in direction and magnitude. AC is commonly used in household and industrial electricity, while DC is used in batteries and electronic devices.

4. How do I calculate the total voltage and current in a series circuit?

In a series circuit, the total voltage is equal to the sum of the individual voltages in the circuit, while the total current is the same at all points in the circuit. This means that you can simply add up the voltage drops across each component to find the total voltage, and the current will be the same at each point in the circuit.

5. What is the significance of voltage and current in a circuit?

Voltage is the driving force that pushes the current through a circuit, while current is the flow of electric charge. Understanding the voltage and current in a circuit is crucial in designing and troubleshooting electrical systems and devices. It also helps in ensuring the safety and efficiency of the circuit.

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