Solving Physics ISU: Electricity & Magnetism Qs - Just Double Check

  • Thread starter altrez
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In summary, the conversation discusses two questions related to electricity and magnetism as part of an ISU for physics. The first question involves a bird standing on an electric transmission line and the calculation of the voltage it feels. The formula V=IR is used to calculate the voltage as 3.6 \times 10^{-3} V. The second question involves the force per metre on a wire carrying a current when perpendicular to a magnetic field. A formula B=\frac {F} {IL} is used to find the force, resulting in a final answer of 2.75 N/m. Feedback is requested on these questions.
  • #1
altrez
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Just two questions that are a small part of my ISU for physics. For this year we had to teach ourselves the unit on electricity and magnetism.

1. A bird stands on an electric tranmission line carrying 1200A. The line has a [itex]1.0\times10^{-5} \Omega[/itex] resistance per metre and the bird's feet are 30cm apart. What voltage does the bird feel.

2. What is the force per metre on a wirde carrying a 2.50A current when perpendicular to a 1.10T magenetic field.

For question one, I was first thinking that since the bird isn't grounded, it shouldn't really feel anything, but since the question probably wouldn't be as easy as that, i guess i'd have to calculate something.

Formula i used was just V=IR
[itex]V = (1200 A)(1.0\times10^{-5} \Omega)(3.0\times10^{-1}m)= 3.6 \times 10^{-3} V
[/itex]

That's what i got as a final answer

For question two, our books didn't really mention anything about formulas with the tesla unit so i guess we had to research it.

I found a formula that was :

[itex]B=\frac {F} {IL} \vspace[/itex]

B is 1.10T
I is 2.50 A
L i think would be 1m since they wanted the force per metre.
F is the unkown

So in the end i got [itex]F = BI

= 1.10T \times 2.50A =2.75 N/m
[/itex]

Just need some feedback on those questions.
 
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  • #2
good job :tongue:
i didn't check your number, but you have applied the formulas correctly
 
  • #3



Great job on your work for these two questions! Your approach and use of the appropriate formulas are correct. For question one, you are correct in thinking that the bird should not feel any voltage since it is not grounded. However, the question is asking for the voltage that the bird feels, not the voltage on the line. So, your calculation of 3.6 x 10^-3 V is correct.

For question two, you have correctly researched and used the formula for the magnetic field. Your calculation of 2.75 N/m is also correct. Just make sure to pay attention to units - in this case, the magnetic field strength should be in Tesla (T) and the current should be in Amperes (A).

Overall, great job on these questions! Keep up the good work on your ISU.
 

What is the difference between electricity and magnetism?

Electricity and magnetism are two different but related forces. Electricity is a force caused by the movement of charged particles, while magnetism is a force caused by the alignment of magnetic fields. In other words, electricity is the flow of charges through a conductor, while magnetism is the creation of a magnetic field by moving charges.

How do I solve problems involving electricity and magnetism?

Solving problems involving electricity and magnetism requires a strong understanding of the fundamental concepts and equations in these areas. It is important to carefully read and understand the given problem, identify the known and unknown quantities, and choose the appropriate equations to solve for the unknown. It is also helpful to draw diagrams and use visual aids to better understand the problem.

What are some common mistakes to avoid when solving physics ISU problems?

One common mistake to avoid when solving physics ISU problems is not carefully reading and understanding the given problem. It is important to identify all the given information and clearly define the unknowns. Another mistake is not using the correct units and not following the correct mathematical procedures. It is also important to double check all calculations and ensure that they make logical sense.

What are some real-world applications of electricity and magnetism?

Electricity and magnetism have numerous real-world applications. Some common examples include the use of electric motors in appliances and vehicles, the generation and transmission of electricity, the use of magnets in speakers and MRI machines, and the use of electricity to power electronic devices such as computers and smartphones. These forces also play a crucial role in the functioning of the human body, such as in nerve conduction and muscle movement.

How can I prepare for my electricity and magnetism ISU?

To prepare for your electricity and magnetism ISU, it is important to review and understand the key concepts and equations in this area. Practice solving different types of problems, and make sure to check your answers and understand any mistakes you make. It can also be helpful to study with a group or seek extra help from a teacher or tutor if needed.

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