Calculating Resistance in a Circuit: Easy Physics Problem Solution

  • Thread starter alvarez16
  • Start date
  • Tags
    Physics
In summary, the conversation discusses a physics problem involving a circuit with a voltmeter, an ammeter, and various resistances. The resistance R is calculated using the voltmeter reading and the current in R, but the ammeter reading is not the same as the current in R. The ratio of the two meter readings gives an apparent resistance R'. The question asks for the ammeter reading, voltmeter reading, and apparent resistance R' when the resistance R is known. The attempted solution includes a drawing of the circuit and calculations for parts A and B, which were incorrect.
  • #1
alvarez16
2
0
Easy Physics problem I just can't get :(

Homework Statement



In figure 27-62, a voltmeter of resistance RV = 380 Ω and an ammeter of resistance RA = 1.18 Ω are being used to measure resistance R in a circuit that also contains a resistance R0 = 100 Ω and an ideal battery of emf ε = 12.0 V. Resistance R is given by R = V/i, where V is the voltmeter reading and i is the current in the resistance R. However, the ammeter reading is not i but rather i', which is i plus the current through the voltmeter. Thus the ratio of the two meter readings is not R but only an apparent resistance R' = V/i'. If R = 61.2 Ω, what are (a) the ammeter reading in milliamperes, (b) the voltmeter reading (in V), and (c) R'?

The Attempt at a Solution



I was able to get part C, 52.71 ohms, which is correct.

I got 90.36mA for part A, and 4.77 V for part B, but both of those are wrong.

Please help me get these!
 
Physics news on Phys.org
  • #2


drawing the figure given may help...
 

FAQ: Calculating Resistance in a Circuit: Easy Physics Problem Solution

1. Why can't I solve this easy physics problem?

There could be several reasons why you are having difficulty solving this problem. It could be due to a lack of understanding of the underlying concepts, not knowing which equations to use, or making mistakes in calculations. It's important to review the basics and practice problem-solving techniques to improve your skills.

2. How can I make physics easier to understand?

Physics can be a challenging subject, but there are ways to make it easier to understand. One approach is to break down complex concepts into smaller, more manageable pieces. You can also try using visual aids or real-life examples to help make connections between theory and practical applications.

3. Can you provide tips for solving physics problems?

When solving physics problems, it's important to read the question carefully and identify what information is given and what is being asked. Then, choose the appropriate equation to use and make sure to use the correct units in your calculations. Finally, check your answer to ensure it makes sense and is in the correct format.

4. How do I know if I'm using the right formula?

Choosing the right formula is crucial in solving physics problems. One way to ensure you are using the correct formula is to identify the known and unknown variables in the problem and see which formula contains those variables. You can also refer to your class notes or textbook for guidance.

5. What should I do if I'm still struggling with physics?

If you are still struggling with physics, don't be afraid to ask for help from your teacher, classmates, or a tutor. Practice regularly and seek out additional resources such as online tutorials or practice problems. Remember to stay persistent and don't get discouraged – with determination and effort, you can improve your understanding of physics.

Back
Top