Induced emf in triangle with changing area

In summary, two straight conducting rails form a right angle, with a conducting bar in contact with the rails starting at the vertex at time t = 0 and moving at a constant velocity of 7.00 m/s. A magnetic field with B = 0.350 T is directed out of the page. At t = 2.50 s, the flux through the triangle formed by the rails and bar can be calculated. The magnitude of the emf around the triangle at that time can also be calculated. If the emf is written as E = at^n, where a and n are constants, the value of n can be determined. Additional information about the length of the non-moving bars may be needed to
  • #1
Hyacinth42
9
0
Two straight conducting rails form a right angle where their ends are joined. A conducting bar in contact with the rails starts at the vertex at time t = 0 and moves with a constant velocity of 7.00 m/s along them, as shown in Fig 31-44. A magnetic field with B = 0.350 T is directed out of the page.

31_56.gif


(a) Calculate the flux through the triangle formed by the rails and bar at t = 2.50 s

(b) Calculate the magnitude of the emf around the triangle at that time.

(c) If we write the emf as E = at[tex]^{}n[/tex], where a and n are constants, what is the value of n?

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Alright, I can figure this out, only I don't know how to find the rate of change of the length of the two non-moving bars. With that, I could find the area at t = 2.50 s, and the change of the magnetic flux, and I could muddle through the last one ;)
 
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  • #2
Add a vertical line in the center of the diagram, from the point where the rails join to the moving bar. You do know the rate of change of this length. Can you express other sides in terms of this length?
 
  • #3
Oh, I see. The height would be vt, and the base would be 2 times the height... Thank you
 

1. What is induced emf in a triangle with changing area?

Induced emf is the electromotive force that is created in a closed circuit when there is a change in the magnetic flux through the circuit. In a triangle with changing area, the magnetic field passing through the triangle changes, which results in an induced emf.

2. How is the induced emf calculated in a triangle with changing area?

The induced emf in a triangle with changing area can be calculated using Faraday's law of induction, which states that the induced emf is equal to the negative rate of change of magnetic flux through the triangle. Mathematically, it can be represented as E = -dΦ/dt, where E is the induced emf and Φ is the magnetic flux.

3. What factors affect the induced emf in a triangle with changing area?

The induced emf in a triangle with changing area is affected by the rate of change of magnetic flux through the triangle, the size and shape of the triangle, and the strength of the magnetic field. Additionally, the material properties of the triangle, such as its conductivity, can also have an impact on the induced emf.

4. What is the significance of induced emf in a triangle with changing area?

The induced emf in a triangle with changing area plays a crucial role in many applications, such as generators and transformers. It is also an important concept in understanding electromagnetic induction and the relationship between electricity and magnetism.

5. Can the induced emf in a triangle with changing area be negative?

Yes, the induced emf in a triangle with changing area can be negative. This occurs when the rate of change of magnetic flux is decreasing. In this case, the induced emf will oppose the change in magnetic flux, resulting in a negative value.

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