B field inside solenoid as a result of iron rod

In summary, a time varying current in a solenoid with a coil of wire placed around it will result in an increase in the B field due to the presence of a soft iron rod inside the solenoid. This increase in the B field will lead to an increase in magnetic flux and an induced emf in the wire according to Faraday's law. As a result, the induced current in the wire will also increase.
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CAF123
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Homework Statement


Consider a solenoid with a time varying current and with a coil of wire placed around it. Suppose there is a soft iron rod inside the solenoid. My question is: What happens to the (induced) current in the coil of wire as a result?

Homework Equations


Faraday, magnetic flux,

The Attempt at a Solution



Since iron is ferromagnetic, (it has associated with it a permanent magnetic dipole moment), it gives out a net B field. So the B field inside the solenoid is increased. Since $$\phi_B = BA,$$ the magnetic flux then increases and hence the induced emf in the wire by Faraday. This causes the induced current to increase also.

Is this okay?

Many thanks.
 
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Looks good.
 

Related to B field inside solenoid as a result of iron rod

1. What is a solenoid?

A solenoid is a type of electromagnetic device that consists of a coil of wire wrapped around a metal core. When an electric current is passed through the wire, it creates a magnetic field in and around the solenoid.

2. How does an iron rod affect the B field inside a solenoid?

The presence of an iron rod inside a solenoid can significantly increase the strength of the magnetic field. This is because iron is a ferromagnetic material, meaning it can easily become magnetized and enhance the overall magnetism of the solenoid.

3. What factors affect the strength of the B field inside a solenoid?

The strength of the B field inside a solenoid is affected by the number of turns in the coil, the current flowing through the wire, and the material and shape of the core. An iron core will increase the strength of the B field, while a larger current or more turns in the coil will also increase its strength.

4. Is the B field inside a solenoid uniform?

In an ideal scenario, the B field inside a solenoid is considered to be uniform, meaning it has the same strength and direction at all points. However, in reality, there may be some variations in the B field due to factors such as the shape and size of the solenoid, as well as the presence of the iron core.

5. What are some practical applications of the B field inside a solenoid with an iron rod?

The B field inside a solenoid with an iron rod has many practical applications, such as in electromagnets used in industrial settings, MRI machines in the medical field, and speakers and electric motors in everyday devices. The increased strength of the B field due to the iron rod allows for more precise and efficient use of electromagnetic forces.

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