# Understanding Magnetic Fields: Compass Pointing in Multiple Directions

• cheff3r
However, the overall direction of the magnetic field will not change, and the compass will still point in the same general direction. Calculating the exact angle of the compass will depend on the specific values of the magnetic fields and the distance from the loop.
cheff3r
This isn't really a home work question but i think it belong in this section, since we are starting to play with compasses in class

## Homework Statement

I was thinking what direction would a compass point if it was placed near a magnetic field (say from a loop of wire) which is at right angles to Earths magnetic field, so then you had two magnetic fields (Earth's and the loop) which will affect the compass

## Homework Equations

Amperes Law and/or Biot-Savart Law

## The Attempt at a Solution

I can see how the compass would point in between the north of the two magnetic fields but at what degree?
here's my attempt at, is it right? so visualise a line from an origin to a point on the xy plane with the strength of the loop is the x distance and the strength of Earths field is the y distance, so the line will end at x,y or B(loop), B(Earth) and now take the line and the y=0 line and you have your angle change.
I have two questions from this,
Firstly am i right in saying the magnetic field will change directions if it is above the loop or in the loop (the right hand rule)? there has got to be a relation ship depending on the distance away from the loop, what is it?
And secondly will the magnetic field strength of the loop drop (spread out) if it is over a larger loop (as in will the magnetic field of the other parts of the large loop affect the compass), how do I calculate for this? or will this be insignificant change to the compass?

any help on any part would be great

! The compass will point in the direction of the resultant magnetic field, which is the vector sum of the Earth's magnetic field and the magnetic field from the loop of wire. You can calculate the strength and direction of the magnetic field using Ampere's Law and/or Biot-Savart Law. The strength of the magnetic field from the loop of wire will depend on the size and shape of the loop, as well as the current passing through it. If the size of the loop is increased, the magnetic field will spread out over a larger area, so its strength at any given point will decrease.

## 1. What is a magnetic field and how does it affect compasses?

A magnetic field is a region in space where a magnetic force can be detected. It is created by moving electric charges, such as those found in magnets or electric currents. This magnetic force can cause compasses to align in a certain direction, typically towards the Earth's magnetic north pole.

## 2. Why do some compasses point in multiple directions?

This phenomenon, known as declination, occurs due to the Earth's magnetic field being tilted at an angle in relation to its geographic axis. This means that the magnetic north pole and the geographic north pole are not in the same location, leading to compasses pointing slightly off from true north.

## 3. Can magnetic fields be manipulated?

Yes, magnetic fields can be manipulated using various methods such as electromagnets or permanent magnets. Scientists can also use magnetic fields to control and manipulate particles in experiments, for example in the field of magnetic resonance imaging (MRI).

## 4. Are magnetic fields important in everyday life?

Yes, magnetic fields play a crucial role in many aspects of our daily lives. They are used in a variety of devices such as motors, generators, and speakers. They also help guide animals like birds and bees in their navigation, and are even used in some forms of alternative medicine.

## 5. Can magnetic fields have negative effects on human health?

While there is some research that suggests long-term exposure to certain types of magnetic fields may have negative effects on human health, the majority of studies have not found any significant harm. The magnetic fields found in everyday devices and environments are generally considered safe for human health.

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