The magnetic flux is a **measure of the number of magnetic field lines passing through an area**. If a loop of wire with an area A is in a magnetic field B, the magnetic flux is given by: If the flux changes, an emf will be induced.

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## Which describes the magnetic flux through a section of a loop?

Which describes the magnetic flux through a section of a loop? It is **a vector that is directed outward through the section**. … When the magnetic field is perpendicular to the section’s area vector. When the magnetic field is in the direction of the section’s area vector.

## How do you find the magnetic flux through a loop?

- Solution: A = π R
^{2}= π ( .040m)^{2}= 0.0050 m^{2}When the loop is horizontal, θ = 0, and the flux is. - Φ
_{1}=BAcosθ =(0.17 T)(0.0050m^{2})(1) = 8.5×10^{–}^{4}Tm^{2}… - Φ
_{2}= B A cosθ = (.17 T)(0.0050m^{2})( 0 ) = 0 Tm^{2}… - Φ
_{2}– Φ_{1}= 0 – 8.5×10^{–}^{4}Tm^{2}= – 8.5×10^{–}^{4}Tm^{2}

## What is induced when the magnetic flux through the loop changes?

As seen in previous Atoms, any change in magnetic flux induces **an electromotive force (EMF) opposing that change**—a process known as induction. Motion is one of the major causes of induction. For example, a magnet moved toward a coil induces an EMF, and a coil moved toward a magnet produces a similar EMF.

## How does Loop area affect magnetic flux?

Faraday’s Law says that the emf induced (and therefore the current induced) in the loop is **proportional to the rate of change in magnetic flux**: … In a coil of wires, each loop contributes an area A to the right-hand side of the equation, so the induced emf will be proportional to the number of loops in a coil.

## Does Loop area affect the current flow?

The loop area effects the flow of current. So, if we **decrease the loop area will are increasing the flow of current**, while increasing the loop area will decrease the flow of current. . 4.

## Which describes the magnetic field lines of a current loop?

Which describes the magnetic field lines of a current loop? **They extend toward the loop on one side and away from the loop on the other side.**

## What is true about a solenoid?

A solenoid (/ˈsoʊlənɔɪd/,) is a type of electromagnet, the purpose of which is **to generate a controlled magnetic field through a coil wound into a tightly packed helix**. The coil can be arranged to produce a uniform magnetic field in a volume of space when an electric current is passed through it.

## Which is true about the emf induced in a loop by a magnet?

Which is true about the emf induced in a loop by a magnet? **It is equal to the inverse of the magnetic flux through the loop**. It is equal to the inverse of the rate at which the magnetic flux through the loop changes. … A loop lies in a magnetic field, with the field perpendicular to the plane of the loop.

## Why is emf max when flux is zero?

As the coil turns and the plane of the coil becomes parallel to the field lines, the flux becomes zero. … By Faraday’s law, the magnitude of the induced emf is equal to the rate of change of magnetic flux, so its maximum values occurs **when the flux curve has its greatest slope**.

## Why is Faraday’s Law negative?

The negative sign in Faraday’s law comes from the fact **that the emf induced in the coil acts to oppose any change in the magnetic flux**. … Lenz’s law: The induced emf generates a current that sets up a magnetic field which acts to oppose the change in magnetic flux.

## How do you find flux?

Find the flux of F=yˆj−zˆk through the paraboloid S=y=x2+z2,y≤1. The flux can be described by **∬SF⋅ndσ with n=2xˆi−ˆj+2zˆk√1+4×2+4z2**. Substitute x2+z2=y to simplify n to −1+2z2y.

## Can you have negative magnetic flux?

**Yes, magnetic flux can be negative**. It just depends on where the field is going. Say there is a sheet and magnetic field is going through it from front to the back, we can call the flux there as positive and negative when it’s the other way round.

## What is a motional EMF?

An emf induced by motion relative to a magnetic field is called a motional emf. This is represented by the equation **emf = LvB**, where L is length of the object moving at speed v relative to the strength of the magnetic field B.

## What increases magnetic flux?

There are three ways to change the magnetic flux through a loop: Change the magnetic field strength (increase, decrease) **over the surface area**. **Change the area of the loop** (increase by expanding the loop, decrease by shrinking the loop)