Find the maximum induced emf in the large coil solenoid

In summary, the question asks to find the maximum induced emf in the large coil, given the parameters of two coils, their respective currents and equations for emf and magnetic field. The solution involves using the equations for magnetic field and flux to find the flux in both the solenoid and outer coil. Then, using Ohm's Law and Faraday's Law, the induced emf can be calculated.
  • #1
kiwikahuna
61
0

Homework Statement


Given: u_0 = 1.25664e-6
A 2 m long large coil with a radius of 14.6 cm and 320 turns surrounds a 4.2 m long solenoid with a radius of 4.6 cm and 7700 turns. The current in the solenoid changes as I = I_0 sin (2pi*f*t) where I_0= 30 A and f=60 Hz.Inside solenoid has 7700turns and outside coil has 320 turns. The equation for the emf is E = E_0sin(omega*t). There is also a resistor on the smaller coil that is 25 ohms. Find the maximum induced emf in the large coil. Answer in units of V.


Homework Equations


Magnetic field = B = u_0 * I / (2*pi*r)
Flux = BA


The Attempt at a Solution


I found the magnetic field of the solenoid (0.069115sin(120*pi*t)) and the area (0.006648). I then multipled BA to find the flux which is (0.000459 sin(120*pi*t))

Then I found the magnetic field of the outer coil ((0.006032sin(120*pi*t)) and the area to be 0.066966.
The magnetic flux is BA = (0.000404sin(120*pi*t))

Now I am truly stuck because I've no clue where to go from here. Please help! Many thanks.
 
Physics news on Phys.org
  • #2
I think Ohm's Law and Faraday's Law would help:

[tex]\displaystyle V = iR[/tex]

[tex]\displaystyle \oint\vec{E}\cdot d\vec{l} = \mathcal{E}_{ind} = -\frac{d\Phi_B}{dt}[/tex]
 
  • #3
Hmm...I'm still lost. Could you perhaps clarify what you mean and how those two equations would relate to each other.
 

1. How is the maximum induced emf in a large coil solenoid calculated?

The maximum induced emf in a large coil solenoid can be calculated using the formula:
Emax = -NΔΦ/Δt, where N is the number of turns in the coil, ΔΦ is the change in magnetic flux, and Δt is the time interval over which the change occurs.

2. What factors affect the maximum induced emf in a large coil solenoid?

The maximum induced emf in a large coil solenoid is affected by the number of turns in the coil, the strength of the magnetic field, and the rate of change of the magnetic field.

3. How does the number of turns in the coil affect the maximum induced emf?

The larger the number of turns in the coil, the higher the maximum induced emf will be. This is because the magnetic flux passing through the coil increases with the number of turns, leading to a larger change in magnetic flux and a higher induced emf.

4. Can the maximum induced emf in a large coil solenoid be negative?

Yes, the maximum induced emf can be negative if the change in magnetic flux is decreasing over time. This would result in a negative value for the emf, indicating a change in direction of the induced current in the coil.

5. How can the maximum induced emf in a large coil solenoid be increased?

The maximum induced emf in a large coil solenoid can be increased by increasing the number of turns in the coil, increasing the strength of the magnetic field, or increasing the rate of change of the magnetic field. Additionally, using a ferromagnetic core inside the coil can also increase the induced emf due to a higher magnetic permeability.

Similar threads

  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
75
  • Introductory Physics Homework Help
Replies
3
Views
150
  • Introductory Physics Homework Help
Replies
15
Views
5K
  • Introductory Physics Homework Help
Replies
3
Views
970
  • Introductory Physics Homework Help
Replies
2
Views
1K
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
2K
Replies
49
Views
3K
  • Electrical Engineering
Replies
1
Views
793
Back
Top