Question about magnetism/induced emf in small coil

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In summary, the problem involves a solenoid with specific dimensions and a current of 1.50 A, along with a smaller coil placed at its center with a resistor connected to its ends. The task is to determine the induced emf in the small coil when the current in the solenoid is switched off within 25 ms. The relevant equation is the induced emf equation, which involves the change in magnetic flux over time. The magnetic flux through the small coil is calculated to be 14.4 x 10^-6 WB, but the change in flux from the solenoid's current being switched off would be (14.4 x 10^-6) - (0), resulting in an induced emf of
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nwyatt
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Homework Statement


A solenoid with a length of 25.0 cm, radius 1.60 cm and 5500 turns carries a current of 1.50 A. A small coil of radius 1.05 cm and 130 turns is placed at the center of the solenoid with its axis in the same direction as that of the solenoid. A 470 ohms resistor is connected to the ends of the small coil. The current in the solenoid is switched off within 25 ms.

Determine the magnitude of the induced emf in the small coil.

Homework Equations



Induced EMF= -N delta [tex]\Phi[/tex] / delta t

The Attempt at a Solution



The main problem I am having is figuring out the change of the magnetic flux. I figured out the magnetic flux through the small coil at 14.4 x10^-6 WB (from the equation magnetic flux=BA cos theta) but I don't know what it changes to or from.
 
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  • #2
Since the current in the solenoid is switched off, it no longer produces a magnetic field. So the flux changes to 0 over the course of 25 ms.
 
  • #3
so for delta [tex]\Phi[/tex] it would be (14.4x10^-6)-(0)?
 

1. What is magnetism?

Magnetism is a fundamental force of nature that describes the attraction or repulsion between objects with magnetic properties. It is caused by the movement of charged particles, such as electrons, within atoms.

2. How is magnetism related to electricity?

Magnetism and electricity are closely related, as they both involve the movement of charged particles. When a current of electricity flows through a wire, it creates a magnetic field, and vice versa. This is known as electromagnetism and is the basis for many modern technologies.

3. What is induced emf?

Induced electromotive force (emf) is the voltage that is created when a conductor, such as a coil of wire, is exposed to a changing magnetic field. This phenomenon is known as electromagnetic induction and is the basis for generators and many other electrical devices.

4. How does a small coil produce an induced emf?

A small coil of wire will produce an induced emf when it is moved through a magnetic field or when the magnetic field passing through it changes. This can also occur when the coil is stationary, but the magnetic field around it changes. The induced emf is proportional to the rate of change of the magnetic field.

5. What factors affect the magnitude of induced emf in a small coil?

The magnitude of induced emf in a small coil depends on several factors, including the strength of the magnetic field, the number of turns in the coil, the speed at which the coil is moving, and the orientation of the coil with respect to the magnetic field. Additionally, the material and resistance of the coil can also affect the induced emf.

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