What is the current in the wire?

[yjk91]

Homework Statement

A square ammeter has sides of length = 8.4 cm. The sides of the ammeter are capable of measuring the magnetic field they are subject to. When the ammeter is clamped around a wire carrying a DC current, as shown in the figure, the average value of the magnetic field measured in the sides is 4.4 G. What is the current in the wire?

http://www.webassign.net/bauerphys1/28-p-026-alt.gif

The Attempt at a Solution

B*4*L=Mo*I

i used this formula

so I = B*4*L/Mo

I = 0.00044 T* 4 * 0.0084 m / (4 pi * 10^-7 ) = 117 A

it's not right it's a little bit off from the answer i think

help?

 

[anathema]

Hello,

Thank you for sharing your solution attempt with us. Let's take a look at your calculations and see if we can identify where the discrepancy might be coming from.

Firstly, your use of the formula B*4*L=Mo*I is correct. This formula relates the magnetic field (B) to the current (I) in a wire of length (L) and permeability of free space (Mo).

Next, let's take a closer look at your numerical values. The magnetic field measured in the sides of the ammeter is given as 4.4 G. However, in your calculations, you used the value of 0.00044 T, which is equivalent to 0.44 G. This could be where the discrepancy is coming from.

Additionally, you used the value of 4 for the length (L) in your calculations. However, the length of the wire in the figure appears to be longer than 4 cm. It may be helpful to measure the length of the wire in the figure and use that value in your calculations instead.

Lastly, make sure to double-check the units of your final answer. The current should be in amperes (A), not in G or T.

I hope this helps! If you continue to have trouble, please feel free to provide more information or ask additional questions. Good luck!