# Calculate Earth's Magnetic Flux at a Certain Location

• muffintop
In summary, the Earth's magnetic field with a magnitude of 5.6x10-5 T and a direction of 72 degrees below the horizontal will result in a magnetic flux of 1.1e-5 Wb through the top of a desk measuring 110 cm by 57 cm. The correct formula to use is \Phi = BA sin \theta, as the desk top is a horizontal surface.

#### muffintop

1. At a certain location, the Earth's magnetic field has a magnitude of 5.6x10-5 T and points in a direction that is 72 degrees below the horizontal. FInd the magnitude of the magnetic flux through the top of a desk at this location that measures 110 cm by 57 cm.
2. I used the formula $$\Phi$$ = BA cos $$\theta$$

## The Attempt at a Solution

$$\Phi[/thex] = 5.6x10-5 x 1.10m x .57m x cos 72 =1.1e-5 Wb and it's wrong muffintop said: 1. At a certain location, the Earth's magnetic field has a magnitude of 5.6x10-5 T and points in a direction that is 72 degrees below the horizontal. FInd the magnitude of the magnetic flux through the top of a desk at this location that measures 110 cm by 57 cm. 2. I used the formula [tex]\Phi$$ = BA cos $$\theta$$

## The Attempt at a Solution

[tex]\Phi[/thex] = 5.6x10-5 x 1.10m x .57m x cos 72
=1.1e-5 Wb and it's wrong

Welcome to PF.

Is the desk top a vertical surface or a horizontal one?

http://hyperphysics.phy-astr.gsu.edu/Hbase/magnetic/fluxmg.html

LowlyPion said:
Welcome to PF.

Is the desk top a vertical surface or a horizontal one?

http://hyperphysics.phy-astr.gsu.edu/Hbase/magnetic/fluxmg.html

Horizontal. and since the I'm looking for the magnetic flux, it should be perpendicular to the area so I use sine instead of cosine. What a stupid mistake haha, thank you for your help!

## 1. What is magnetic flux?

Magnetic flux is a measure of the total magnetic field passing through a given area. It is represented by the symbol Φ.

## 2. How is magnetic flux calculated?

Magnetic flux is calculated by taking the dot product of the magnetic field vector and the surface normal vector of the area through which the magnetic field passes. This is represented by the equation Φ = B*A*cos(θ), where B is the magnetic field, A is the area, and θ is the angle between the magnetic field and the surface normal.

## 3. What is the unit of measurement for magnetic flux?

The unit of measurement for magnetic flux is the weber (Wb) in the International System of Units (SI).

## 4. How does the Earth's magnetic flux vary at different locations?

The Earth's magnetic flux varies at different locations due to the Earth's magnetic field, which is not uniform. It is affected by factors such as the Earth's rotation, the movement of molten iron in the Earth's core, and the interaction between the Earth's magnetic field and the solar wind.

## 5. What factors can affect the accuracy of calculating Earth's magnetic flux at a certain location?

The accuracy of calculating Earth's magnetic flux at a certain location can be affected by factors such as the strength and direction of the Earth's magnetic field, the shape and orientation of the area being measured, and the precision of the measuring instruments used.