Electromagnetism exam tomorrow

In summary, the conversation discusses a homework question involving two charges at specific distances and a given tension. The equation E=\frac{kQ}{r^2} is mentioned, but the attempt at a solution does not use all the given data and results in an incorrect answer. The potential difference U is also mentioned, but its relation to the electric field E is not clear.
  • #1
nunos
7
0
Have exam tomorrow. I know I should have studied before and more, but please help. If you know the answer, please take some time to reply. Thanks very much.

Homework Statement



There are two charges, q1 = +4.5nC, and q2, ?, which are at distances d1 = 2.5cm and d2 = 2.0cm, from a point which has the tension of 3.2kV. What is the value of q2?

Homework Equations



[tex] E = \frac{kQ}{r^2} [/tex], I think that's all, but I most probably am wrong.

The Attempt at a Solution



This is certainly wrong. I have not even used one of the data given. Anyone, that's the best I was able to come up with.

[tex] \frac{kq_1}{r_1^2} = \frac{kq_2}{r_2^2}[/tex]

which gives [tex]q_2 = 1.28 * 10^{-6} [/tex] which is a wrong answer, since the correct one is supposed to be [tex]3.5nC[/tex].
 
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  • #2


You have not used that the potential difference U is 3.2 kV.
What does potential have to do with (difference in) electric field E?
 

1. What topics should I focus on for the electromagnetism exam tomorrow?

The electromagnetism exam will likely cover topics such as electric fields, magnetic fields, electromagnetic waves, and the properties of conductors and insulators. It is important to review these concepts and understand their applications.

2. How can I prepare for the electromagnetism exam?

To prepare for the electromagnetism exam, it is important to review class notes, textbook chapters, and any study guides provided by the instructor. Practice problems and quizzes can also help to reinforce your understanding of the material.

3. What equations do I need to know for the electromagnetism exam?

You should have a strong understanding of the fundamental equations of electromagnetism, including Coulomb's Law, Gauss's Law, Faraday's Law, and Ampere's Law. It is also important to know how to apply these equations to solve problems.

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The electromagnetism exam will likely include a mix of both calculations and conceptual questions. It is important to be able to apply the equations and concepts to solve problems, but also to have a strong grasp of the underlying principles of electromagnetism.

5. Are there any helpful resources or study materials I can use to prepare for the exam?

Aside from class notes and textbooks, there are many online resources available to help you prepare for the electromagnetism exam. These can include practice problems, video tutorials, and interactive simulations that can help you visualize and understand the concepts. You can also reach out to your instructor or classmates for additional study materials.

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