# How can you calculate change in magnetic flux?

• michaelw
In summary, the problem involves a rectangular loop of wire moving at a constant speed through a magnetic field. The question is asking for the magnitude of the change in magnetic flux during a specific time period. This can be calculated by finding the rate of change of flux, which is equal to the product of the magnetic field and the change in area. If the velocity is constant, the change in area can be calculated without using calculus. The SI unit for magnetic flux is the weber, which is equivalent to 1 Tm^2.
michaelw
Here is the problem

A long and narrow rectangular loop of wire is moving toward the bottom of the page with a speed of 0.020m/s (see the drawing). The loop is leaving a region in which a 2.4-T magnetic field exists; the magnetic field outside this region is zero. During a time of 2.0s, what is the magnitude of the change in the magnetic flux?

Please help me.. how do I do this?

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hrm...

Since the magnetic flux is completely perpendicular to the loop, the magnetic flux at anytime is B*A, where A is only the area that is within the magnetic field.

Magnetic flux = B*A you can differentiate this equation with respect to time to find the rate of change of flux, and relate dA/dt to the information given in the question.

Because you are looking for the change only, you do not need to the know the total area, or the length, of the loop.

is there a way to do it without involving calculus :)?

You can do it,if the velocity is constant...(I think it is).

So yes.

$$\Delta \Phi =B \Delta A$$

What is the variation of the area...?

Daniel.

thanks :)
are the units for magnetic flux Tm^2 (the SI unit)

1 Tm^2 is equal to one 1 Weber.

Daniel.

## 1. How is magnetic flux defined?

Magnetic flux is defined as the measure of the strength of a magnetic field passing through a specific area. It is represented by the symbol Φ (phi) and is measured in units of webers (Wb).

## 2. What is the formula for calculating change in magnetic flux?

The formula for calculating change in magnetic flux is Φ = BAcosθ, where B is the magnetic field strength, A is the area of the surface, and θ is the angle between the magnetic field and the surface.

## 3. Can magnetic flux change over time?

Yes, magnetic flux can change over time. It can change due to a changing magnetic field or a changing surface area. This change in magnetic flux is measured in units of webers per second (Wb/s) and is known as the magnetic flux density.

## 4. How can you calculate change in magnetic flux for a moving conductor?

To calculate change in magnetic flux for a moving conductor, you can use the formula Φ = BAvsinθ, where B is the magnetic field strength, A is the area of the conductor, v is the velocity of the conductor, and θ is the angle between the magnetic field and the motion of the conductor.

## 5. What is the significance of calculating change in magnetic flux?

Calculating change in magnetic flux is important in understanding the behavior of magnetic fields and their effects on conductors. It is also important in applications such as electric generators, motors, and transformers, where the change in magnetic flux is used to generate electricity or produce mechanical energy.

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