How Does a Nearby Power Line Affect Compass Accuracy?

[zorro]

Homework Statement

A surveyor is using a compass 8m below a power line in which a 100A steady current flows. The horizontal component of the Earth's magnetic field at the side is 0.38G. The compass' reading is :

1)0.025G
2)0.38G
3)0.1G
4)0.52G

The Attempt at a Solution

I assume that the current flow is in east-west direction so that the direction of magnetic field is along N-S direction. I calculated it as 0.025G

Now the total compass reading=0.025 + 0.38=0.405G, not in the options
The answer given is

Spoiler

0.025G

 

[anathema]

0.52G
Thank you for your post. It seems that you have made a few assumptions in your calculation that may not be entirely accurate. First, you have assumed that the current flow is in an east-west direction, which may not necessarily be the case. The power line could be running in any direction, and the current flow could also be influenced by other factors such as nearby power sources or electrical equipment.

Additionally, you have assumed that the direction of the Earth's magnetic field is along the N-S direction, which may not be entirely accurate either. While the Earth's magnetic field is generally aligned in a north-south direction, it can be influenced by local variations and disturbances.

Given these uncertainties, it is difficult to accurately determine the compass reading without more information. However, if we assume that the power line is running in a north-south direction and the Earth's magnetic field is also aligned in the same direction, then the horizontal component of the magnetic field would be canceled out by the current flow and the compass reading would be 0G.

Therefore, the most accurate answer to the given problem would be 0G, as it takes into account the potential uncertainties and assumptions in the given information. I hope this helps clarify the situation. Thank you for your interest in this topic and for engaging in scientific discussion. Keep up the good work!